Imaginova Starry Night Pro 5.0 User’s Guide, Starry Night Pro 5.0 User Manual

284 Richmond St. E. Suite 300 Toronto, ON M5A 1P4, Canada
www.starrynight.com
©2004 Imaginova Corp. All rights reserved. Starry Night and Imaginova are trademarks of Imaginova Corp.
Microsoft and Windows are trademarks of Microsoft Corporation. Apple, Macintosh, Mac, and QuickTime are registered trademarks of Apple Computer, Inc. OpenGL® is a registered trademark owned by Silicon Graphics, Inc.
Printed in Canada.
Table of Contents
Getting Started
Welcome ..................................................................... 7
Outline Of This User’s Guide ..................................... 8
Starry Night Companion ............................................. 9
Special Fonts ............................................................... 9
Installing Starry Night Pro 5.0 .................................... 9
Running Starry Night Pro 5.0 ................................... 12
Registering ................................................................ 12
Data Updates ............................................................. 13
Setting Your Home Location .................................... 14
Starry Night For the First Time................................. 15
Getting Help .............................................................. 15
Program Updates....................................................... 16
Starry Night Website................................................. 16
Basics
10 Important Features ............................................... 17
Using The Controls ................................................... 18
Changing Your Viewing Direction ........................... 20
Changing The Date And Time .................................. 20
Identifying Objects In The Sky ................................. 21
Labeling Objects ....................................................... 22
Displaying Constellation Figures.............................. 22
Finding Objects ......................................................... 23
Zooming In On Objects............................................. 24
Learning More About Objects .................................. 27
Printing Star Charts ................................................... 27
Tool Selection Control .............................................. 28
Appearance of the Sky
Sky Contextual Menu................................................ 31
Options Pane ............................................................. 32
Light .......................................................................... 33
Changing the Horizon ............................................... 35
Displaying Celestial Objects ..................................... 36
4 Starry Night Pro 5.0 User’s Guide
Labeling Celestial Objects ........................................ 37
Celestial Object Display Options .............................. 38
Star Display Options ................................................. 39
Star Brightness, Contrast & Colour .......................... 41
Planet Display Options.............................................. 42
Comet, Asteroid & Satellite Display Options........... 44
Messier/Bright NGC/User Images Display Options. 44
Milky Way Display Options ..................................... 45
Tully Database Display Options ............................... 45
Selecting Filaments and Groups ............................... 46
Other Object Display Options ................................... 47
Label Options ............................................................ 47
Constellations............................................................ 48
Guides 1 (Co-ordinate Systems) ............................... 50
Guides 2 (Display Options)....................................... 52
Field of View Indicators 1
(Creating an Equipment List).................................... 54
Field of View Indicators 2
(Displaying Indicators) ............................................. 56
Flip ............................................................................ 58
Heads-Up Display (HUD) Options ........................... 58
OpenGL Options ....................................................... 59
Number Formats ....................................................... 60
White Sky Mode ....................................................... 61
Night Vision Mode.................................................... 61
Full Screen Mode ...................................................... 62
Saving Your Settings ................................................ 62
Sky Data
SkyGuide................................................................... 66
SkyCalendar .............................................................. 67
DVD Movies ............................................................. 70
LiveSky Pane ............................................................ 71
Status Info ................................................................. 72
Downloading Photographic Images .......................... 75
Online Telescope Imaging ........................................ 76
Object Databases
Introduction to Databases.......................................... 78
Databases 1 (Solar System)....................................... 78
Databases 2 (Stars).................................................... 79
Databases 3 (Deep Space)......................................... 80
Databases 4 (Other)................................................... 81
Database Updates ...................................................... 83
Find Pane Info........................................................... 85
Object Contextual Menu ........................................... 86
Info Pane ................................................................... 88
LiveSky.com Object Database .................................. 94
Bending Space & Time
Time Flow ................................................................. 98
Time Flow Modes ..................................................... 99
Local and Celestial Paths ........................................ 100
Changing Your Viewing Location .......................... 102
Changing Elevation................................................. 104
Location Mode ........................................................ 106
Orientation .............................................................. 107
Orbits....................................................................... 108
Spaceship Mode ...................................................... 110
Piloting the Spaceship ............................................. 111
Special Tools
Telescope Control ................................................... 114
Observation Planner ................................................ 116
Graph....................................................................... 119
Ephemeris Generator............................................... 121
Working With Files
What is a Starry Night Pro 5.0 File? ....................... 124
File Features ............................................................ 124
The Favourites Menu .............................................. 125
Creating Files - An Example................................... 126
Multiple Windows................................................... 127
Exporting Images .................................................... 128
Making Movies ....................................................... 129
Movie Compression Settings .................................. 130
Playing Back QuickTime Movies ........................... 131
Making QuickTime Virtual Reality Files ............... 131
Quicktime VR Movie Settings ................................ 132
Exporting Sky Data................................................. 132
Adding Your Own Data
Adding Log Entries ................................................. 135
Adding Calendar Events ......................................... 137
Adding Objects 1 (Solar System Objects) .............. 139
Adding Objects 2 (Multiple Solar System Objects) 146
Adding Objects 3 (Stars)......................................... 146
Adding Objects 4 (Databases)................................. 147
User Images............................................................. 148
Modifying Images ................................................... 152
Custom Horizons..................................................... 152
Photorealistic Horizons ........................................... 153
Customizing the Favourites Menu .......................... 153
Custom Asterisms ................................................... 155
Backing Up Custom Data ....................................... 155
5
6 Starry Night Pro 5.0 User’s Guide
Frequently Asked Questions
QuickTime .............................................................. 159
Registration Number ............................................... 160
Installation............................................................... 161
Support .................................................................... 161
Updates/Upgrades ................................................... 161
General Run-Time Problems .................................. 162
OpenGL................................................................... 162
Time & Date............................................................ 163
Viewing Location.................................................... 165
Internet Database & Digitized Sky Survey ............. 166
Printing & Making Movies ..................................... 166
Telescopes ............................................................... 167
Constellations & The Zodiac .................................. 167
Solar System Bodies ............................................... 168
Stars......................................................................... 169
Keyboard Shortcuts ...................................... 171
Index..................................................................... 173
Chapter 1
Getting Started
Welcome
The invention of desktop astronomy software has been the most exciting new development in the astronomy hobby in years, perhaps since that night four centuries ago when Galileo pointed the newly invented telescope at the heavens for the first time! Starry Night Pro 5.0 is the premier astronomy software package on the market, putting more power and knowledge in your hands than even the world’s pre-eminent astronomers had just a few years ago.
You can see how the sky will look tonight, tomorrow, or far into the past or future. You can view the stars as they appear from your own backyard, from a country on the other side of the world, or from another planet. You can witness a total eclipse from the Moon, watch the Sun set from the surface of Mars, or even ride a comet. You are limited only by your curiosity.
This guide is designed to help you harness the full power of Starry Night Pro 5.0. Enjoy the ride!
8 Starry Night Pro 5.0 User’s Guide
Outline Of This User’s Guide
All users of Starry Night Pro 5.0 should read chapters 1 and 2 of this User’s Guide to get a basic grasp of how to use the program. After this, you may want to explore the program on your own and only refer to the User’s Guide if you have questions about a specific feature. Alternately, you may wish to read the entire User’s Guide. Below is a brief summary of each chapter in the User’s Guide.
Chapter 1: “Getting Started to get Starry Night Pro 5.0 up and running for the first time.
Chapter 2: “Basics frequently used features in the program.
Chapter 3: “Appearance of the Sky you how to modify the onscreen appearance of Starry Night Pro 5.0.
Chapter 4: “Sky Data more information about astronomy and the sky in general.
Chapter 5: “Object Databases the different types of celestial objects included in Starry Night Pro 5.0 and the information you can learn about each object.
” covers the most
” tells you how
” shows
” shows you to get
” describes
simulations to demonstrate astronomical concepts.
Chapter 7: “Special Tools of Starry Night Pro 5.0’s astronomy tools that go beyond displaying the sky. Some examples are telescope control and observation planning and logging.
Chapter 8: “Working With Files you how to save files, capture colour images and make QuickTime videos using Starry Night Pro 5.0.
Chapter 9: “Adding Your Own Data teaches you how to expand the vast library of data that is built into Starry Night Pro
5.0. You will learn how to create your own constellation sets, add custom images, and even build your own databases!
Appendix A: “Frequently Asked
Questions” answers the questions most
commonly asked by users of Starry Night Pro 5.0.
Appendix B: “Keyboard Shortcuts handy reference table listing the Windows and Mac keyboard shortcuts for the features in Starry Night Pro 5.0.
” describes some
” teaches
” is a
Chapter 6: “Bending Space & Time a detailed look at the features of Starry Night Pro 5.0 that let you visit other locations in the universe, view the sky from dates in the past or future, and modify the speed at which time in Starry Night Pro 5.0 moves forward. This section will be particularly useful for educators who plan to use Starry Night Pro 5.0
” takes
Getting Started 9
Starry Night Companion
This User’s Guide will teach you how to use Starry Night Pro 5.0. The second book included with your package, Starry Night Companion, is a guide to learning more about astronomy and the night sky. This 200 page book, written by astronomer John Mosley, is your tour guide to the uni­verse and will help you appreciate what you see when you are outdoors looking up at the night sky.
You can access an electronic version of Starry Night Companion by choosing Help->Companion Book from the main menu.
Quick Start User Card
This handy reference card walks you through the installation process and offers tips on how to use the most common Starry Night functions.
Special Fonts
Two special fonts are used throughout this User’s Guide:
1) Command Font: This font is used to indicate a button, clickable area, keystroke, or menu choice.
Examples:
1 Click the Online Info button.
2 Press the Ctrl-Alt-Delete keys.
3 Choose File->Open from the menu.
2) File Font: This font indicates a folder or file, either on your hard drive or the Starry Night Pro 5.0 CD. File and folder names are always enclosed in quotations.
Examples:
1 Locate the “satellites.txt” file
on the CD.
2 Your preferences are saved in the
“Starry Night Pro 5.0 \Sky Data\Prefs” folder.
Installing Starry Night Pro 5.0
Starry Night Pro 5.0 comes on three CD’s that include both the Windows and Macintosh versions. To run Starry Night Pro 5.0, you need to install two programs: Starry Night Pro 5.0 and QuickTime. QuickTime is a tool for manipulating graphics files and constructing and viewing animation sequences. Starry Night Pro 5.0 will not run if QuickTime (version 6.5 or later) is not installed. To install Starry Night Pro 5.0 and QuickTime, follow the installation instructions below.
Note: If you already have QuickTime (version 6.5 or later) on your computer, you do not need to install it again. If you have an older version of QuickTime, install the newer version of QuickTime from the Starry Night Pro 5.0 CD. It will automatically overwrite your older version.
10 Starry Night Pro 5.0 User’s Guide
Windows:
Insert disc 1 in the CD-ROM drive.
1
2 A window will pop up onscreen with
instructions on installing Starry Night Pro 5.0. Follow the instructions that appear and insert the next disc when prompted. The “Full Install” option will install extra star data, with stars as dim as magnitude 16 (these stars are not visible in your sky without a telescope) and the Principal Galaxy Catalog (PGC) with 980, 000 galaxies as dim as magnitude 18. The “Minimal Install” option will not install these dimmer stars and galaxies, and will save about 300 MB of hard disk space. The “Custom Install” option allows you to select which extra data to install.
work unless you choose this option.
4 During the installation process, a
window may open which allows you to enter a QuickTime registration number. This number is only for a more advanced version of QuickTime that is not included with Starry Night. Leave this screen blank and hit the Next button. Do NOT enter your name or Starry Night registration number.
3 At the end of the installation, the Starry
Night installer launches an application to install QuickTime. Follow the instructions that appear onscreen. You will be asked to select an installation option for QuickTime. Choose the “Recommended Install” option. Certain Starry Night features will not
Getting Started 11
5 At one point in the installation process,
there will be a screen titled "File Type Associations". Press the File Types button to edit the associations.
6 Make sure that only the box marked
"Quick Time Movie" is checked under the Video category. This will associate .mov files correctly with QuickTime. Other movie file types (for example, mpeg or avi files) will not be affected.
Tip: The first time you enlarge an image or play a movie, you may see the Get QuickTime Pro window. Click Later. You do not need to upgrade to QuickTime Pro to see multimedia files in Starry Night.
7 Following the QuickTime installation,
the Starry Night installer launches an application to install telescope control. If you have a motorized telescope you wish to control with Starry Night Pro
5.0, follow the onscreen instructions. See “Telescope Control
” on page 114 for more information on telescope control.
.
8 Starry Night Pro 5.0 includes a
standalone DVD disc (“SkyTheater”), which contains short movies about astronomy. You can play the DVD disc on your computer DVD-ROM drive or your home DVD player.
12 Starry Night Pro 5.0 User’s Guide
Macintosh: To install Starry Night Pro 5.0
for the Macintosh, follow these steps.
1 Insert disc 1 into the CD-ROM drive
and double-click on the Starry Night Pro 5.0 installation icon. Insert the next discs when prompted. The “Full Install” option will install extra star data, with stars as dim as magnitude 16 (these stars are not visible in your sky without a telescope) and the Principal Galaxy Catalog (PGC) with 980, 000 galaxies as dim as magnitude 18. The “Minimal Install” option will not install these dimmer stars and galaxies, and will save about 300 MB of hard disk space. The “Custom Install” option allows you to select which extra data to install.
Tip: Macintosh users do not need to install a separate driver for telescope control, it is packaged into the main Starry Night Pro
5.0 installer.
Macintosh: Double-click the Starry Night
Pro 5.0 icon in the Applications folder, or click the icon on your dock.
Registering
When you run Starry Night Pro 5.0 for the first time, you will be prompted to enter your name and registration number. To get your unique registration number, click Get Registration Number. For this to work, you must have an active Internet connec­tion. If you do not have an active Internet connection, you can still click OK and the program will operate normally—but you will not be able to download the periodic data updates, such as new comets, upcom-
ing events and tours
.
2 Starry Night Pro 5.0 includes a
standalone DVD disc (“SkyTheater”), which contains short movies about astronomy. You can play the DVD disc on your computer DVD-ROM drive or your home DVD player.
Running Starry Night Pro 5.0
Once you have installed Starry Night Pro 5.0, you can run the program as follows:
Windows: Double-click the Starry Night
Pro 5.0 icon on your desktop, or select it from your start menu.
Registering makes it possible for us to notify you of any upgrades, bug fixes, or plug-ins as they become available. You may also be eligible for reduced upgrade prices to other astronomy software programs. You can update your registration information at any time in the future by visiting
www.starrynight.com/register
.
Getting Started 13
Tip: You can retrieve your registration number at any time by choosing Registration from the Help menu (Windows) or the Starry Night Pro 5.0 menu (Macintosh).
After you have typed in your name and registration number, press OK to begin Starry Night Pro 5.0.
Data Updates
The first time you run Starry Night Pro
5.0, a window will pop up that asks if you wish to update your data files.
If you press Update Files, Starry Night Pro
5.0 will attempt to connect to our website and download updated data files. Downloading these files ensures that any new comets, asteroids, satellites, calendar events or tours are added to the program. If you do not want to download updated data files at this time, just press Cancel to skip this process. You can update these data files at any time in the future by choosing
LiveSky-> Update Comets/Asteroids/Satellites from
the menu. See “Database Updates page 83 for more information on updating data files.
” on
Only registered users can download the updated data files. If you did not register Starry Night Pro 5.0, the following window will appear onscreen when you try to download new data files:
Click Open Registration Dialog to obtain your registration number and proceed with updating your data files or click Cancel File Update to continue without downloading.
Note: Updating data files is not the same as updating the program itself. To ensure that you are running the latest version of Starry Night Pro 5.0, see “Program Updates
” on page 16.
14 Starry Night Pro 5.0 User’s Guide
Setting Your Home Location
The first time Starry Night Pro 5.0 runs, a dialog box opens that asks you to set your home location. Once you have done this, you do not need to change your home location unless you move.
1 Click the List tab. This displays a huge
database of cities throughout the world.
2 Use the scrollbar on the right to look
through the list. If your home city is listed, click on its name to highlight this city and press the Save As Home Location button. If your city is not listed, proceed to step 3.
Tip: A list of astronomical observatories is included in the location list. To see this list, click on the Province column heading and scroll down to “Observatories”.
minutes.You must also enter the correct time zone. Time zones are calculated according to the time difference from London, England. For example, all communities on Eastern Standard Time are 5 hours behind London, so you would enter “-5 h” if you are on Eastern Standard Time. If you do not know your latitude, longitude, or time zone, click Lookup Lat/Long on Internet for Internet resources that will help you find this information.
4 Once you have entered your co-
ordinates, click the Add Location to List button. This will open a window where you can enter your city, province/state and country. Press the Add Location button once you have entered this information., then press the Save As Home Location button.
3 Click the Latitude/Longitude tab. Type
in the name of your location and enter your latitude and longitude. You can enter these values in degrees, degrees & minutes, or degrees, minutes & seconds. Starry Night Pro 5.0 will convert your values to degrees and
Getting Started 15
Tip: If you ever move and need to change your location (or if you initially enter your home location incorrectly), choose Set Home Location from the File menu (Windows) or the Starry Night Pro 5.0 menu (Macintosh) to enter a new home location.
Starry Night For the First Time
After you have entered your home location, the main screen of Starry Night Pro 5.0 appears. This window shows what you would see if you stepped outside at the current time, and looked south from your home location. Direction markers along the horizon help you orient yourself. If you open the program at night, you see a star­filled night sky. If you open the program during the day, you see a daytime scene with blue sky and sunshine. A horizon is shown to give you some perspective.
The current time is shown in the upper left corner of the screen.
The next chapter will show you how to use them and become more comfortable with the program.
Getting Help
Hopefully this User’s Guide will help you master Starry Night Pro 5.0! But if you still have questions, there are plenty of places to turn for help.
Contextual Help: Hold
the cursor over any of Starry Night’s controls, and a text box will pop up that describes the function
of that control.
Info Icon: Whenever you see this icon
beside one of the controls in Starry Night Pro 5.0, click the icon to see a short description of that control.
Electronic Manual: Choosing
Help->User’s Guide from the menu opens the PDF version of this manual.
Note: The current date and time are calculated from your computer’s clock. If your computer’s clock is incorrect, Starry Night Pro 5.0 may show night when it is day outside, or vice versa. See “Time & Date
” on page 163 if you do not know how to change your computer’s clock settings.
Most of the controls in Starry Night Pro
5.0 will probably look unfamiliar to you.
Tech Support Website: A list of frequently
asked questions is included in Appendix A: “Frequently Asked Questions
”. An
up-to-date version of this FAQ is available online by choosing Help->Online Help from the menu. Any new bugs or other issues regarding Starry Night Pro 5.0 will be covered in this FAQ.
16 Starry Night Pro 5.0 User’s Guide
Discussion List: The Starry Night
Discussion List is a newsgroup that allows you to ask questions and share tips with other owners of Starry Night Pro 5.0. At press time, the Discussion List had more than 6000 members, so it is an excellent resource. Sign up for this list at http://
www.starrynight.com/support/ discussion_lists.html
Contact Technical Support: You can
contact our technical support staff at http://
www.starrynight.com/support/ for help
with your problems.
Program Updates
Starry Night Pro 5.0 is updated on a fairly regular basis. Updates may add new features, or may fix bugs in the existing program. To find out if you are running the latest version, choose About Starry Night Pro 5.0 from the Starry Night Pro 5.0 menu (Macintosh) or the Help menu (Windows). A new window will open, and this window will have your version number in the bottom left corner.
running the most up-to-date version of Starry Night Pro 5.0.
Starry Night Website
More information about Starry Night Pro
5.0 and other astronomy programs is available at our website,
www.starrynight.com
.
Once you know your current version number, choose LiveSky->Check For Program Updates from the menu. This will take you to the updates section of our website. If any updates are available, instructions for downloading and installing these updates will be provided. We recommend that you check for program updates soon after you install the program, to ensure that you are
Chapter 2
Basics
It is impossible to cover all of the features of Starry Night Pro 5.0 in one short chapter. However, you will use certain features much more than others. This chapter will show you how to use the 10 most important features in Starry Night Pro 5.0. Once you have read this chapter, you will be able to use Starry Night Pro
5.0 effectively as a guide to the night sky.
10 Important Features
Here are the 10 tasks you will learn to perform with Starry Night Pro 5.0 in this chapter:
1 Use the controls.
2 Change your viewing direction.
3 Change the date and time.
4 Identify objects in the sky.
5 Label objects.
6 Display constellation figures.
7 Find objects.
8 Zoom in on objects.
9 Learn more about any object.
10 Print star charts.
18 Starry Night Pro 5.0 User’s Guide
Using The Controls
All of the controls in Starry Night Pro 5.0 are in three areas of the screen: the toolbar, the side panes, and the menu. There is more than one way to access many of the features in Starry Night Pro 5.0 - for example, you may be able to access a feature through the main menu and through the side panes.
Tip: If some of the controls described in this section appear to be missing from your version of Starry Night Pro 5.0, you may not have installed QuickTime correctly. Reinstall QuickTime and be sure to choose the “Recommended Install” option, and you should then see all of the controls. See “Installing Starry Night Pro 5.0
” on
page 9 for more information.
Toolbar: The toolbar is the strip of buttons
which runs just above the main window. The toolbar has the following controls (each set of controls is explained in a later section):
Tool Selection
Tip: Clicking the blue pin button on
the toolbal will display a menu with all the log entries you have added to Starry Night Pro 5.0. See “Adding Log Entries
” on page 135 for more information on observing logs.
Side Panes: These panes are along the left
side of the screen.
Clicking on a pane causes the pane to slide out, revealing a set of controls. Each pane opens to a default width. However, by clicking along the right edge of the pane and dragging the mouse, you can make the pane narrower or wider.
Within a pane, you can expand or collapse various
layers by using these buttons:
Expand layer (Windows).
Expand layer (Macintosh).
Collapse layer (Windows).
Collapse layer (Macintosh).
You can hide the toolbar by choosing View->Hide Toolbar from the main menu.
Time and Date
Time Flow Rate
Viewing Location
Gaze
Zoom (FOV)
Layer (expanded)
La
Layer (collapsed)
Pane
Basics 19
Each of the side panes controls an important function in Starry Night Pro 5.0, and is explained in detail in a later section.
Pane Page
Find
Options
Favourites
Status
Info
SkyGuide
SkyCalendar
Planner
LiveSky
FOV
Telescope
85
32
125
72
88
66
67
116
71
56
114
Button Bar (Windows only): On
Windows, the button bar provides an additional set of controls. The button bar is located under the menu, just above the toolbar. It contains a set of buttons for some of the most commonly used functions in the program. Point the cursor at one of the buttons, and a text tip will pop up that describes the button’s function.
Tip: You can hide the button bar at any time by selecting View->Hide Buttonbar in the menu. If you prefer to hide the button bar, you can still access all of its controls through the other menus and tools. You can also turn off the text tips for the button bar by choosing Preferences from the File menu (Windows) or the Starry Night Pro 5.0 menu (Macintosh), choosing General from the dropbox in the upper left corner of the Preferences dialog box, and unchecking the “Show button help on scroll over” box.
Menu: The menu runs across the top of the
screen, above the toolbar. Clicking on an item in the menu expands the menu to reveal additional options.
20 Starry Night Pro 5.0 User’s Guide
Changing Your Viewing Direction
By default, Starry Night Pro 5.0 always opens with your view facing south, looking slightly above the horizon. You can then adjust this view to look in any direction.
Tip: If you would prefer that Starry Night Pro 5.0 open with your view facing in a direction other than south, choose Preferences from the File menu (Windows) or the Starry Night Pro 5.0 menu (Macintosh), choose General from the dropbox in the upper left corner of the Preferences dialog box, and adjust the “Default Viewing Direction” ring slider. You can also adjust the default altitude (how high above the horizon you are looking).
The default cursor icon in Starry
Night Pro 5.0 is a hand. When you hold the mouse button down, you will see the hand close, as if it is “grabbing” part of the sky. If you hold the mouse button down and drag the mouse, your view shifts in the direction that you moved the mouse. The compass icon in the upper right corner of the screen shows the direction in which you are viewing. You can also use the compass points marked along the horizon to find your viewing direction.
above the horizon, you may see a red marker. This marker identifies the
zenith,
the point in the sky that is directly above your head. If you are located in space, you can also look straight down to see a marker for the
nadir, the point directly
beneath your feet. If you are located on Earth or another planet, you are limited in how far down you can look. You are able to look only slightly below the horizon, and cannot see the nadir. If you wish, you can turn off the markers for the zenith and nadir by choosing Preferences from the File menu (Windows) or the Starry Night Pro 5.0 menu (Macintosh), choosing General from the dropbox in the upper left corner of the Preferences dialog box, and unchecking the “Show zenith and nadir while scrolling” box.
Changing The Date And Time
When you open Starry Night Pro 5.0, you may see a bright blue sunny sky, a dark sky filled with stars, or a twilight realm with only a few bright stars showing. This is because Starry Night Pro 5.0 always opens showing the sky at the current date and time. The date and time are shown in the upper left corner of the toolbar.
Tip: You can configure Starry Night Pro
5.0 to display scroll bars along the edges of the window by selecting View->Show Scroll Bars from the menu. You can then use these scroll bars in place of the hand to adjust your viewing direction.
Zenith and Nadir Markers: If you adjust
your view so that you are looking high
Tip: A small icon of the Sun appears to the left of the time in the
toolbar. If Daylight Saving Time is turned on, this icon is lit up. Starry Night Pro 5.0 uses your computer clock to determine if Daylight Saving Time should
Basics 21
be turned on. Click on the icon to turn on or off Daylight Saving Time.
See “How does Daylight Saving Time
work in Starry Night?” on page 164 for
more information on Daylight Saving Time.
To change the date or time, just click on it. The date or time will light up, and you can type in a new value.
If Starry Night Pro 5.0 is showing a daytime scene, try changing the time so that it is night. If you already see a night scene, change the time so that it is day. Starry Night Pro 5.0 allows you to set the date from anywhere between 99 999 BC and 99 999 AD.
Tip: As you are working through the rest of the features in this chapter, you will probably want to set the time in Starry Night Pro 5.0 so that the sky is dark. In the day, only the Sun will be visible onscreen, and it will be difficult to use some of the features.
Special Times:
Immediately to the right of the time display in the toolbar is a pull-down menu that lets you quickly change the time to one of
several key times.
sunset, moonrise or moonset. You can also change to Sun is highest in the sky, or
solar noon, the time at which the
moon transit,
the time at which the Moon is highest in the sky.
Moon Calendar: Clicking the
SkyCalendar pane will open a pane showing a calendar with moon phase information. See “SkyCalendar
” on page 67 for more information on the Calendar.
Identifying Objects In The Sky
If you point the cursor at any object shown onscreen, information about the object will automatically appear. This is Starry Night Pro 5.0’s
Heads-Up Display (HUD).
Displayed are the object’s name, the constellation it is in, and its distance (if known) from Earth. This makes it easy to identify any of the points of light displayed onscreen.
You can reset the time to the current time by pressing Now or set the time to sunrise,
22 Starry Night Pro 5.0 User’s Guide
You can choose which information fields are displayed when you point the cursor at an object. See “Heads-Up Display (HUD) Options page 58 for more details.
Labeling Objects
The Heads-Up Display is great for finding out what a specific object is, but it’s not much help if you want a quick overview of all of the brighter objects onscreen. The best way to quickly identify all bright objects is to choose Labels->Show All Labels from the menu. This labels the brightest objects in each category (stars, constellations, planets, deep space objects). You can turn these labels off again by choosing Labels->Hide All Labels.
” on
Displaying Constellation Figures
For thousands of years, stargazers have joined the brighter stars together into patterns that we call constellations. Astronomers currently recognize 88 constellations, which together cover the entire sky. Knowing which constellation an object is in is the first step to finding the object.
You can turn on the stick figures for the constellations by choosing View->Constellations->Astronomical from the main menu. Choosing this option again will remove the figures. Use the Labels menu to turn on/off the constellation labels.
Starry Night Pro 5.0 offers much more precise control over object labels. You can label only certain types of objects, increase/decrease the number of labels, or label only the objects that you select. See “Labeling Celestial Objects for more information.
” on page 37
Many more options exist for displaying the constellations. These options are outlined in “Constellations
” on page 48.
Finding Objects
If you are interested in finding a specific object, such as a planet or a bright new comet, open the
Find side pane. Click in the text box at the top of this pane and type in the first few letters of the object you are looking for. As you type, Starry Night Pro 5.0 displays a list of objects that match your name.
Once the object that you are looking for appears in the list, double-click on its name, and Starry Night Pro 5.0 will centre on the object. Several information fields are listed beside each object in the list of found objects. See “Find Pane Info
” on
page 85 to learn what these fields mean.
Tip: The object you are searching for may be hidden beneath the horizon. If this is the case, Starry Night Pro 5.0 will offer you the option of hiding the horizon or advancing the time forward to a time when the object will be above the horizon. Objects below the horizon are greyed out.
Basics 23
Panning To Found Objects: By default,
Starry Night Pro 5.0 slowly pans to objects that you have double-clicked on in the Find pane. This feature is handy because it allows you to see where the new object is relative to your current view. If you choose Preferences from the File menu (Windows) or the Starry Night Pro 5.0 menu (Macintosh) and choose Responsiveness from the dropbox in the upper left corner of the Preferences dialog box, you will see a slider and checkbox named “Pan to found objects”. Adjusting the slider changes the speed at which Starry Night Pro 5.0 pans to found objects. Unchecking the box disables the panning feature completely, so that your view changes instantly to the “found” object as soon as you double-click on it.
Tip: If you hit the space bar during a pan, the program immediately takes you directly to the object. If something catches your eye and you want to stop the pan, press the Esc key.
Searching Specific Databases: By default,
Starry Night Pro 5.0 searches all of its object databases when you use the Find pane.
If you wish, you can choose to search in only a specific database, by clicking the arrow on
the left side of the textbox in the Find
24 Starry Night Pro 5.0 User’s Guide
pane, and choosing the appropriate database from the menu that appears. “Object Databases
” on page 77 describes each of the object databases included in Starry Night Pro 5.0.
Enhanced Find: By default Starry Night
Pro 5.0 searches for objects whose name begins with the first letters typed in the text box at the top of the Find pane. Clicking on the dropbox that reads “begin with’ opens a menu with additional search options. You can customize your search by selecting to find objects that exactly match, contain or end with the letters you entered in the text box.
Solar System Object List: If you clear the
text box at the top of the Find pane, the list of items found is replaced by a list of solar system objects.
Click the symbol to the left
of an object’s name to expand the list to include all other objects that orbit this object.
For example, clicking on this
symbol for Mars will expand the list to include the moons of Mars. Clicking again collapses the list and hides Mars’s moons. You can double­click on any object in this list to centre on the object in Starry Night Pro 5.0’s main window.
Zooming In On Objects
Now that you know how to find objects, you will probably want to know how to zoom in for close-up views of spectacular objects such as Saturn and the Andromeda Galaxy.
The amount of sky that you can see is called the
field of view. If it was possible
to see the entire hemisphere of sky that is above the horizon at any time, you would have a 180° field of view. Of course, this is impossible. Including some peripheral vision, the human eye can see approximately a 100° field of view. If you look through binoculars, the area you see is a much smaller piece of the sky, which means binoculars have a correspondingly smaller field of view (usually 5° to 7° ). Telescopes have an even smaller field of view than binoculars.
Starry Night Pro 5.0 opens with a 100° field of view. We call this the normal field of view, since it approximates a view of the sky that you would see with your own eyes. Along the top right corner of the
Basics 25
toolbar is a set of zoom buttons which adjusts your field of view.
Clicking the zoom button on
the right zooms in (reduces your field of view), while clicking the button on the left zooms out (increases your field of view). Clicking the left zoom button and holding your mouse button restores your field of view to 100°. It is important to remember that when you zoom in on objects, you are not in fact changing your location. Think of zooming as looking through a more and more powerful telescope, while your feet remain firmly planted.
Note: You can also use the Magnification tool to adjust your field of view. See “Magnification Tool
” on page 28 for more
information on the Magnification tool.
Your exact field of view is always listed in the Zoom control of the toolbar. If you click on the arrow to the right of the Zoom display, a pull-down menu opens which allows you to choose from several preset fields of view.
Note: When you zoom in to a very small field of view, your field of view will be shown in
arcminutes. If you zoom in even
closer, your field of view will be shown in
arcseconds. One arcminute is 1/60 of a
degree, and one arcsecond is 1/60 of an arcminute. The smallest field of view which Starry Night Pro 5.0 can display is 1 arcsecond.
The compass image in the upper right corner (visible only when you
are using the field of view controls or changing your viewing direction) provides an excellent graphical interpretation of the field of view. This image shows how large a patch of sky is being displayed in your current view. As you zoom in, the patch of sky shrinks. As you zoom out, the patch of sky expands. The compass image also shows your viewing direction.
Tip: To hide the compass, open the
Options pane, expand the Guides layer and uncheck the “Show compass indicator while scrolling” box.
Maximum Zoom Out: By default, you are
unable to zoom out past the standard view of 100°. To zoom out to see an even larger field of view, choose Preferences from the File menu (Windows) or the Starry Night Pro 5.0 menu (Macintosh), choose General from the dropbox in the upper left corner of the Preferences dialog box, and check the box marked “Allow Maximum Zoom Out”. Then continue zooming out using the left zoom button until you have a circular field of view of 180°, which is the entire hemisphere of sky that is above the horizon at any one time. This is the view of the sky that most planispheres (handheld circular star charts) represent.
26 Starry Night Pro 5.0 User’s Guide
Changing the Zoom Step: If you choose
Preferences from the File menu (Windows) or the Starry Night Pro 5.0 menu (Macintosh) and choose Responsiveness from the dropbox in the upper left corner of the Preferences dialog box, you will see a slider named “Zoom Step”. This slider adjusts the rate at which Starry Night Pro 5.0 increases and decreases your magnification when you use the Zoom buttons. By setting this slider farther to the right, you will zoom in or out faster, because each zoom step will be larger.
Angular Separation: Angular separation
provides another way of understanding fields of view and angles in the sky. If you point at an object and click and hold the left mouse button and then drag the mouse to a second object, a line appears which connects the two objects. The
separation
between the two objects is displayed, along with the direction of the line and the actual distance between the two objects (if known).
angular
The angular separation measures how far apart in the sky two celestial bodies appear. The entire sky is divided into 360°, so an object which is directly in front of you and an object directly behind you in the sky have an angular separation of 180°. If you measure the angular separation between two objects on opposite sides of your screen, you should find that it is very close to the field of view that Starry Night Pro 5.0 is showing. Note that the angular separation of two objects has no connection to how far apart these objects really are: two bodies which appear side by side in the sky may be hundreds of light years apart!
Example: Magnifying Jupiter
1Open the “Jupiter”.
2 Double-click on Jupiter’s name in the list to centre on Jupiter. If a dialog box shows that Jupiter is beneath the horizon, choose the
3 If Starry Night Pro 5.0 is displaying a daylight sky, choose from the menu to turn off daylight.
4 Click the “+” zoom button to slowly zoom in on Jupiter. As you zoom in, Starry Night Pro 5.0 automatically shows dimmer stars. Once your field of view reaches about 30 arcminutes, Jupiter will start to look like a ball instead of a point.
Find pane and type in
Hide Horizon option.
View->Hide Daylight
5 Continue clicking the “+” zoom button all the way until your field of view is about
Basics 27
6 arcminutes. Note that Jupiter will still not fill the screen.
6 Press the “+” zoom button to continue zooming in on Jupiter. Once you reach a field of view of about 35 arcseconds, Jupi­ter should fill the screen.
7 Click the “-” zoom button and hold your mouse button down to restore your field of view to 100
°.
Learning More About Objects
For any object displayed onscreen in Starry Night Pro
5.0, you can double-click on
the object to learn more about it. Double­clicking will open the Info pane, which has information on the object organized into different categories. All of the information fields in the Info pane are described in detail in “Info Pane
” on page 88.
Tip: Right-clicking (Ctrl-click on the Mac) on any object onscreen will open a contextual menu of options. Select Show Info from this menu to open the Info pane and learn more about the object.
Printing Star Charts
Starry Night Pro 5.0 has a special set of print settings which make printing informative, legible charts a snap. You can then take these charts outside to help with your stargazing.
Centre on the area of sky you are interested in, and use the zoom buttons to set the correct field of view for your printed chart. For example, if you want a chart that shows the entire sky, centre on the zenith, and set your field of view to 180°. Remember that the appearance of the sky is time-sensitive, so make sure to set the time in Starry Night Pro 5.0 to the time that you plan to go outside to observe!
Once you have set the time, viewing direction and field of view, select File->Print from the menu. You will get a full-page printout of the area shown onscreen.
Print Settings: If you choose
Preferences->General from the File menu (Windows) or the Starry Night Pro 5.0 menu (Macintosh), you will see the options “Use print settings when printing” and “Use current settings when printing”. These options control the appearance of your printed chart: how many stars are shown, how many objects are labelled, etc. “Use print settings” will print star charts using Starry Night Pro 5.0’s special print settings file, while “Use current settings” will print charts using the same settings that you currently have onscreen. You can also create custom print settings. See “Customizing Print Settings
” on page 62
for more information.
28 Starry Night Pro 5.0 User’s Guide
Tip: If you choose
Options->Presets->Print Settings from the menu, Starry Night Pro 5.0 will apply its special print settings to your screen view. This allows you to see how a star chart printed with these settings would look.
Tip: If you are interested in viewing a dim object, and it is not labeled on the printed chart you make, select it on the screen by pointing the cursor at the object and clicking on it. Its name should then appear on screen with an arrow pointing to the object. This is known as “selecting” an object. See “Labeling Select Objects
” on page 37 for more information on selecting objects. If you print a new chart, the selected object will now be labelled.
Tool Selection Control
Now that you know about some of the major features in Starry Night Pro 5.0, we’ll take a quick look at the Tool Selection Control. This control (in the upper left corner of the toolbar, to the left of the time controls) alters the functionality of the cursor, giving you easier access to a variety of the program’s features.
replaces the mouse pointer on your computer screen.
Arrow Tool: Highlights objects in the
sky. To select multiple objects, press the Shift key while making selections.
Hand Tool: Changes the direction in
which you are viewing. Use this tool to drag the sky to the left or right, up or down, until you reach the area you want to see.
Tip: When using any other tool, you can temporarily switch to the Hand tool by holding down the keyboard’s space bar.
Constellation Tool: Selects
constellations. Choose this tool and click anywhere in the sky to select the constellation that contains that point.
Location Scroller: Changes the latitude
and longitude from which you are observing. Dragging up or down adjusts your latitude, while dragging left or right adjusts your longitude. For example, while viewing from Earth, you can use this tool to quickly travel anywhere on the Earth’s surface.
The Tool drop down menu contains a number of selections. To use a tool, click on its name. When selected, the tool’s icon
Tip: This tool is particularly useful when youve lifted off into space and want to adjust your view of the planet below you.
Angular Separation Tool: Displays the
angular separation between two objects, as seen from your current viewing position. Select the tool, click on one object, and drag to another.
Magnification Tool: Magnifies your
current view. Select the tool and click
anywhere in the window to zoom in that direction. To magnify a specific area of the sky, hold down the mouse button and drag to encompass the area you want magnified.
Tip: Holding down the Ctrl key (Windows) or the Option key (Macintosh) while using the Zoom tool zooms you back out.
QTVR Tracker Tool: Changes your
viewing direction. Unlike the hand tool, you don’t drag the sky around. When you hold down the mouse button, the cursor changes from a bull's eye icon to an arrow icon that points in the direction you move the mouse. The sky will move in the direc­tion you are moving the cursor, and moves faster the further you move the cursor with the mouse button down. If a line appears in front of the arrow cursor, it means you have reached the limit of scrolling in that direction. The QTVR tool is a fast way of moving around the sky.
Basics 29
Adaptive Hand Tool: By default, the
adaptive hand tool is selected. This tool allows you to change your viewing direction. However, unlike the regular Hand Tool, the adaptive hand tool can change to other tools automatically. For example, it will change to a selection tool when you point to a selectable object, a location scroller when viewing from space or an angular separation tool when you click-hold on an object and drag to another.
30 Starry Night Pro 5.0 User’s Guide
Chapter 3
Appearance of the Sky
Unlike the real world, Starry Night Pro 5.0 allows you to modify the sky’s appearance to best suit your needs. You can display illustrations of the classical constellations, show only the artificial satellites circling overhead, or customize your view in dozens of other ways. This chapter will look at all of the functions that let you modify Starry Night Pro 5.0’s simulation of the night sky.
Sky Contextual Menu
You can open a contextual menu in Starry Night Pro 5.0 by pointing the cursor at any area of the sky and right­clicking (Ctrl-click on the Mac). If you are pointing the cursor at a specific object, the contextual
menu will provide options specific to that object. If you were not pointing the cursor at a specific object, the menu gives you options for the appearance of the sky as a whole and the constellation which you are pointing at. Many of the most used functions relating to the appearance of the sky are in this contextual menu (for example, turning the horizon on/off, turning daylight on/off, turning light pollution on/off).
32 Starry Night Pro 5.0 User’s Guide
Options Pane
Many of the options for modifying the appearance of the sky are in the Options pane. The Options pane is organized in a layered framework, based on the distance of various celestial objects from Earth. Controls for altering the appearance of the sky are slotted into the appropriate layer. For example, controls for adjusting the appearance of the planets fall into the “Solar System” layer. Any of the layers in the Options pane can be expanded by clicking the expand button to the left of the layer’s name.
3 Stars. Controls for objects outside the
solar system, but inside the Milky Way. For example, stars, extrasolar planets, and the appearance of the Milky Way itself.
4 Deep Space. Controls for objects
outside our galaxy. For example, other galaxies.
Tip: This layer also includes databases that include objects both within and outside of our galaxy. For example, the Messier database includes globular clusters, which are inside our galaxy, but it also includes other galaxies, so it is classified in the “Deep Space” layer.
Guides and constellations do not fall naturally into this layered scheme, so they are given their own layers. Finally, certain databases overlap with other databases, so their controls are placed in the “Other” layer. See “Databases 4 (Other)
” on page 81 to see which objects fall into this category.
Most controls fall naturally into one of four layers. These layers correspond with different databases - see “Introduction to Databases
” on page 78 for
a description of these databases.
1 Local View. Controls that affect the
view of the sky from your location. For example, turning the horizon on/off.
2 Solar System. Controls for objects in
our solar system. For example, planets, comets, and asteroids.
Appearance of the Sky 33
Most of the object classes listed in the Options pane have special options associated with them. Clicking on the object name in the pane will open a dialog box with options for that object class. For example, clicking on the word “Comets” in the Options pane (“Solar System” layer) will open a dialog box with options for altering the appearance of comets.
Light
Many celestial objects are only visible during certain times of the year. At other times in the year, they are above the horizon only during the daytime, when they are washed out by the Sun’s light. With Starry Night Pro 5.0, you can get around this problem by selecting View->Hide Daylight from the menu, or unchecking “Daylight” in the Options pane (Local View). This turns on or off the effects of a planet’s atmosphere, including the scattering of light which makes our sky appear blue. If it is daytime and you turn daylight off, you will be able to see the stars which are normally hidden.
Tip: This feature works on any planet which has an atmosphere. On Mars, the atmosphere scatters sunlight and makes the sky look pink. Turning off daylight eliminates this effect. Our Moon has no atmosphere, so turning daylight off on its surface has no effect.
Tip: Use the brightness slider to the right of an object class name to control how bright these objects appear onscreen.
Brightness Slider
Light Pollution: There may be times when
you want to add light, instead of eliminating it. This is because the default night view in Starry Night Pro 5.0 assumes the observer is far from bright lights, under dark skies. As a result, many stars are visible, perhaps too many for the urban stargazer.
Even on a perfectly cloudless and moonless night, an observer in a big city will not see anywhere near the number of
34 Starry Night Pro 5.0 User’s Guide
stars which his or her counterpart in the country will see. Starry Night Pro 5.0 allows you to mimic the effects of light pollution, showing only the brighter stars and making the sky more closely resemble what you see from home. To turn light pollution on or off, check or uncheck the “Light Pollution” box in the “Local View” layer of the Options pane.
Distant Light Pollution: Even when we
live in an area of low local light pollution there is often a source of artificial light on the horizon. A nearby city for example, can create a light pollution dome, washing out celestial objects that are low on the horizon. You can add light pollution domes for one or more nearby cities.
Click the “+” button in the Distant Light Pollution section of the dialog box to bring up another dialog box that will allow you to name the light source, set the direction and control the intensity of the light pollution dome.
To add the light pollution dome of a nearby city, click on “Distant Light Pollution” in the “Local View” layer of the Options pane. This will open a dialog box with options for adding distant light pollution sources.
Your new distant light pollution entry will be added under “Distant Light Pollution” in the Options pane (“Local View” layer).
Tip: You can also turn on light pollution by right-clicking (Ctrl-click on the Mac) on the background sky in the main window. This will open a contextual menu with two light pollution options: Local Light Pollution and Distant Light Pollution.
Tip: Another way to customize light pollution levels is to specify a limiting magnitude for celestial objects, especially stars. See “Constrain
” on page 38 for
more information.
Changing the Horizon
By default, Starry Night Pro 5.0 shows a photorealistic horizon. However, there may be times when you wish to hide the horizon (for example, to view a close-up image of an object that is beneath the horizon). You can turn the horizon on/off by checking/unchecking the “Local Horizon” checkbox in the Options pane (“Local View” layer), or by choosing View- >Hide Horizon from the main menu. By choosing Options->Other Options->Local Horizon
Appearance of the Sky 35
from the main menu, a dialog box with options for changing the horizon appears.
Horizon Style: You can choose from one of
three horizon types. Flat horizons have no variation in elevation or scenery. Custom horizons are illustrated horizons with images of trees, hills and clouds. See “Custom Horizons information on modifying custom horizons. Photorealistic horizons are panoramic images. A pull-down menu lets you choose from one of several horizon images and also cloud types.
Note: If you do not have an OpenGL compatible graphics card, you will not be able to view the photorealistic horizons, so you will probably want to use the custom horizon type.
Options: The standard horizon view is
opaque, but you can make it semi­transparent by checking “Translucent” or reduce the horizon to a thin line by checking “Outline”. This will help you determine which objects and
” on page 152 for
36 Starry Night Pro 5.0 User’s Guide
constellations are about to rise above the horizon.
By default, Starry Night Pro 5.0
displays compass points on the horizon. If you find that you don’t use or need them, you can turn them off by unchecking “Show Compass Points”.
Displaying Celestial Objects
Checkboxes in the Options pane for each database of celestial objects let you turn on or off these databases. See “Object Databases complete listing of the object databases included in Starry Night Pro 5.0. You can turn databases on/off so that only the objects that you are interested in appear onscreen. For example, you may want to find out which of the many points of light shown onscreen represent planets. By turning the database of stars off, it will be much easier to identify the planets.
” on page 77 for a
If a database is turned off, no objects from this database will be displayed. However, if a database is turned on, not all of the objects in the database will be displayed. There are two reasons for this. First, several databases are very large. It would be impossible for Starry Night Pro 5.0 to draw all 16 million stars in its database onscreen at one time! Second, Starry Night Pro 5.0 strives to present a realistic representation of the sky, so it only shows those objects bright enough to be visible. As you zoom in to a smaller field of view, dimmer objects are automatically shown (remember that zooming in is equivalent to looking through a more powerful telescope). Many databases have options that let you adjust how many objects are displayed. See “Celestial Object Display Options page 38 for more information.
By default, all databases are turned on, with the exception of those databases in the “Other” layer, which are turned off because they may overlap with the core databases. See “Databases 4 (Other) page 81 for a listing of these “other” databases.
” on
” on
Tip: You can also turn databases on/off by choosing View from the main menu and checking the appropriate database.
Appearance of the Sky 37
Labeling Celestial Objects
In “Labeling Objects
” on page 22, you learned how to turn on labels for all types of objects. You can also selectively choose which types of objects to label. To the right of each database listed in the Options pane is a “labels” checkbox. Checking this option will label the brightest members of this database. Labeling certain object types makes it easier to identify these objects. For example, deep space objects may be hard to identify among the glare of the brighter stars and planets. By labeling only deep space objects, these objects will be easy to locate.
change the label colour for selected objects by choosing Preferences from the File menu (Windows) or the Starry Night Pro 5.0 menu (Macintosh), choosing General from the dropbox in the upper left corner of the Preferences dialog box, and clicking on the “Selection colour” rectangle.
Database Label Options: You have great
control over how labels appear in Starry Night Pro 5.0. You can change, the size, colour, font and number of labels for each database. See “Label Options
” on page 47
for more information.
Tip: You can also turn database labels on/ off by choosing Labels from the main menu and checking the appropriate database.
Labeling Select Objects: If you only want
to label a few specific objects, point the cursor at the first object, and click the left mouse button. This “selects” the object, and its label will appear, along with an arrow pointing to the object. For subsequent objects, hold down the Shift key and click on the object. You can deselect all objects by choosing Edit->Select None from the menu. You can
38 Starry Night Pro 5.0 User’s Guide
Celestial Object Display Options
As mentioned in “Displaying Celestial
Objects” on page 36, clicking on a
database name in the Options pane will open a dialog box with display options for that database. The options fall into two categories: options for displaying the objects in the database, and options for displaying the labels for these objects. This section focuses on the options for displaying the objects, while “Label Options
” on page 47 will look at
label options.
Tip: You can also access database options by choosing Options from the main menu and selecting the appropriate database.
Some display options are common to all object databases, while some are specific to certain databases.
displayed onscreen. Moving the slider to the right will display more objects.
Constrain: If this box is checked, only
objects that fall within the
magnitude
range that you specify will be
apparent
displayed onscreen. For example, if you live in a city, and your naked eye
magnitude
is around 4.00, you could use
limiting
this function so that Starry Night Pro 5.0 displays all stars whose magnitudes are between -2 and 4. That way, what you see on the computer screen will be similar to what you actually see while observing from your urban location.
You may also want to use this control to simulate your telescope view on a given night. If you know the magnitude of the dimmest star that your telescope can make out, setting the “Dimmer” end of the slider to this magnitude gives you a good idea of what you can view through your instrument.
Most (but not all) databases have these three options:
Number of objects: This slider controls
how many objects from this database are
Tip: The “Constrain” function only displays a subset of the objects that would be shown if this function was turned off. For example, assume you want to increase the number of stars onscreen so that all stars brighter than magnitude 7 are visible. If you are at a 100° field of view, then Starry Night Pro 5.0 will only show stars up to a magnitude of 5.7, by default. Increasing the apparent magnitude range using the “Constrain” function would have no effect. To increase the number of stars shown, you would first move the “Show” slider farther to the right (so that stars as dim as magnitude 7 are now visible), and then use the “Constrain” function to ensure that no stars dimmer than magnitude 7 are shown.
Appearance of the Sky 39
Many databases have unique options. We will look at these options in the next few sections.
Star Display Options
There are more options for displaying stars than for any other database of objects in Starry Night Pro 5.0. Many of these options can be turned on/off from a checkbox in the Options pane, while clicking the option name will often open a dialog box with more controls.
Click the words “Limit by Distance” in the Options pane to open a dialog box that lets you set numeric values for limiting by distance or magnitude.
Mark Binaries/Mark Variables/Mark Stars With Extrasolar Planets:
These options let you display special markers for variable stars (stars whose brightness varies), binary stars (double stars that orbit around a common center of mass), or stars that are known to harbour planets. Variable stars are marked with one of four symbols, according to how much they vary in brightness.
Limit By Distance/Magnitude: These
options let you set up Starry Night Pro 5.0 to display only those stars whose distance from Earth or whose apparent magnitude (brightness) fall within a certain range. One use of this function would be to identify which bright stars are within 100 light years (for example) of Earth.
Tip: If you turn on markers for extrasolar planets, the star’s Info pane will include information about the extrasolar planet, such as the planet’s mass and distance from its central star. See “Extrasolar planet information fields
” on
page 92 for more details.
Proper Motion Vectors: Every star is
moving rapidly through space, in a unique direction. However, because the stars are so far away, they appear to remain in the same place in the sky. Only over thousands of years can we see the stars shift position with respect to each other. This slow
40 Starry Night Pro 5.0 User’s Guide
movement of the stars is called proper
. Starry Night Pro 5.0 lets you
motion
display proper motion vectors, lines that represent the speed and direction of each star’s motion. The length of a star’s proper motion vector indicates its relative speed.
The Proper Motion Options dialog box has a “vector scaling” option that allows you to change the length of all proper motion vectors, and a “vector colour” option that allows you to change the colour of these vectors.
Additional Star Options: The main Star
Options dialog box lets you control how many stars are displayed and how they are labeled.
It also has a “3D Positions” slider that lets you determine how many stars are drawn in the correct position in 3-dimensional space. This feature is only useful when your viewing location is outside the solar system, in such a manner that you can see the 3-dimensional arrangement of the stars in our solar neighbourhood. See “Changing Your Viewing Location
” on page 102 to learn how to change your viewing location. “Only show 3D stars when outside Solar System” hides those stars for which we do not have accurate 3­dimensional positions, making it easier to see the 3-dimensional structure of our solar neighbourhood.
Appearance of the Sky 41
Example: Isolating the Hyades Cluster
This example will show you how to use the star display options to separate stars in the Hyades cluster from other stars.
1 Turn off daylight and hide the horizon by checking the appropriate boxes in the
Options pane (“Local View” layer).
2 Ensure that the star database (in the “Stars” layer of the on, and the “Bright NGC Objects” database (in the “Deep Space” layer) is turned off. We need to do this because the Hyades is an object in the “Bright NGC Objects” database - and that would be too easy!
3Open the “Epsilon Tauri”. This is a bright star in the Hyades cluster. Double-click on this star’s name to centre on the Hyades cluster.
4 Use the zoom buttons in the toolbar to zoom in to a field of view of about 15°.
5 Turn on proper motion vectors for stars, using the checkbox in the (“Stars” layer). Increase the length of proper motion vectors to maximum, by pulling the “Vector scaling” slider in the “Proper Motion Vectors Options” dialog box all the way to the right. You should see that many of the stars have vectors pointing in the same direction, indicating that they are moving together through space and are part of the same cluster. However, many other stars, such as the bright star Aldebaran, are moving in very different directions.
6 Open the “Limit by Distance Options” dialog box for stars. Check “Limit stars by distance” and set the distance range from 140 to 170 light years, the distance of the Hyades cluster. This will cause almost all stars that do not belong to the cluster to disappear, leaving only stars in the Hyades cluster, all with proper motion vectors pointing in the same direction. Those few stars with vectors pointing in different directions (likely not cluster members) are now very easy to identify.
Options pane) is turned
Find pane and type in
Options pane
Star Brightness, Contrast & Colour
Starry Night Pro 5.0 gives you complete control over the brightness, contrast, and colour of star display. To access these options, choose Preferences from the File menu (Windows) or the Starry Night Pro
5.0 menu (Macintosh) and select Brightness/Contrast from the dropbox in the upper left corner of the Preferences dialog box.
The Star type dropbox lets you choose from several different types of star images.
This preference will be applied to every star drawn onscreen. Try testing out each of these different star images and seeing which one you prefer.
The “Min/max star size” slider determines how large stars appear onscreen.
The Range slider increases or decreases the size distinction between the brightest
42 Starry Night Pro 5.0 User’s Guide
and dimmest objects in the sky, while the Contrast slider increases or decreases the colour distinction between the brightest and dimmest objects in the sky. If you’re viewing from an urban location, you may want to decrease the contrast so that Starry Night Pro 5.0’s display is closer to your physical view. If you’re viewing from a rural location, you can increase the contrast to view a more diverse night sky.
A star’s colour is determined by its surface temperature, ranging from blue (hottest) to red (coolest). The Colour slider increases and decreases the extent to which Starry Night Pro 5.0 displays star colour. Pulling the Colour slider to the right shows more and more of the full spectrum of star colours, to an extent you would never see from Earth. Pulling the Colour slider to the left strips away colour distinctions until all stars appear white.
Planet Display Options
Starry Night Pro 5.0 gives you many options for the display of our Sun and its planets and moons. A variety of guides are also available to give you perspective.
At a 100° field of view, planets are displayed like stars, which is how they appear to us from Earth’s surface. As you get closer to a planet (by zooming in on the planet or by changing your location) you begin to see the disc image and any phase information.
Starry Night Pro 5.0 depicts the planets using the latest images from NASA and other space agencies. Unfortunately, we have not yet been able to fully image all of the objects in our solar system. Where little or no data is available, Starry Night
Appearance of the Sky 43
Pro 5.0 uses the time-honored tradition of deploying space artists to create the surfaces of distant worlds as seen from space, such as Pluto, Charon, and Saturn’s moon Phoebe.
Several of the planet images in Starry Night Pro 5.0 were created or enhanced by astronomy enthusiasts. Choose Help->Image Credits from the menu to see thumbnails and credits for the planet surface images and the images of deep space objects.
Earth/Moon Shadow Outlines: Earth and
the Moon cast shadows upon one another in certain alignments with the sun. The two circles of this target represent the limits of the umbral and penumbral shadows projected out at the Earth/Moon distance. The umbral shadow encloses the area experiencing a total eclipse, while the penumbral shadow encloses the area experiencing a partial eclipse. This feature is useful when watching a solar eclipse from the Moon — you can see the Moon’s shadow approaching Earth before it actually casts its shadow upon Earth.
Show Atmosphere: You can turn off the
atmospheres of objects that possess an atmosphere, such as the Sun, Venus, and Earth. This allows you to see the rocky surface of Venus, instead of seeing the almost featureless cloud cover. Turning the Sun’s atmosphere off shows the Sun as it would appear when viewed through a hydrogen-alpha filter.
Surface Guides: You can turn on several
types of guides to help you determine a planet’s orientation in space, or to locate features on the planet surface.
The grid draws planetary lines of latitude and longitude. You can also turn on the planet meridian and equator lines. The pole sticks show you the north and south poles of the planet. Grid numbers mark the lines of latitude and longitude on the grid.
In the following image, we magnified Jupiter and turned on all of its surface guides.
Dark Side: For more realistic and exciting
viewing, you can choose to display the dark sides of planets. The slider lets you control the sharpness of the transition between the dark and lit side.
Specular Reflection: This feature is only
available with OpenGL graphics cards. It realistically models the Sun’s glare.
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Comet, Asteroid & Satellite Display Options
Brightness: For these three classes of
objects, a slider lets you adjust the apparent brightness of the objects. For comets, the slider actually adjusts the brightness of the comet tail. You also have the option to turn comet tails off entirely.
Orbit Colour: This rectangle lets you
choose a new colour for the orbit lines of these objects. See “Orbits
” on page 108
for more information on object orbits.
Messier Objects/Bright NGC Objects/User Images Display Options
These databases have a specific image associated with each object. Most of the images from the “Messier” and “Bright NGC Objects” databases were photographed by astronomy enthusiasts. Choose Help->Image Credits from the menu to see thumbnails and credits for the planet surface images and the images of deep space objects.
Starry Night Pro 5.0 lets you adjust the brightness of images using the slider provided. Using this control, you can adjust the image so that its brightness appears as it would through a backyard telescope (as a very dim image), or as captured by a long exposure observatory photograph (a much brighter image). You also have the option of selecting to display the outlines for these objects instead of their images.
Milky Way Display Options
By default, Starry Night Pro 5.0 displays a stunning photographic image of the band of the Milky Way. If you find this image is too bright, you can use the Brightness slider to tone down the image brightness, or uncheck the Milky Way box in the Options pane, to turn off the image entirely.
Tully Database Display Options
One of the core databases in Starry Night Pro 5.0 contains 28 000 nearby galaxies plotted in 3-D. This database was compiled by astronomer Brent Tully and colleagues, hence it is referred to as the Tully Collection. This galaxy database is very special because it shows the 3-D position in space of each galaxy, not just the galaxy’s position as seen from Earth.
In Starry Night Pro 5.0 you have great control over how this database is displayed onscreen. To open the “Tully Database Options” dialog box, click on the words “Tully 3D Database” in the Deep Space layer of the Options pane.
Appearance of the Sky 45
You will find the following options:
Bounding boxes: If you have “Entire
dataset” checked, all galaxies will be surrounded by a 3-dimensional box, letting you see the spacial area occupied by the Tully Collection. “Selected filaments/ groups” will only draw a box around the filaments/groups you have selected.
Magnification: When a galaxy is very
close, it is represented by a full-colour image instead of a dot. This slider lets you enlarge these galaxy images. The “correct” position of the slider is all the way to the left-this will draw galaxies the proper size, and you will rarely see more than one or two galaxy images onscreen at the same time. Moving the slider to the right allows you to see many galaxy images at the same time, producing some spectacular views.
Visibility range: Use this slider to display
only those galaxies that lie within a certain range. If you move the slider all the way to the left, only those nearby galaxies that are bright enough will be displayed, moving
46 Starry Night Pro 5.0 User’s Guide
the slider all the way to the right will display all the galaxies in the Tully Collection at the same time.
Colour saturation: Each different type of
galaxy is represented with its own colour image. The dots used to represent a distant galaxy are the same colour as the full-size image. Moving this slider to the right makes the colour of the dots closer to that of the galaxy image, while moving the slider to the left strips away all colour distinctions until all galaxies are represented by white dots. The advantage of having the slider far to the right is that you can quickly identify galaxy type, for example, a cluster of blue dots indicates a group of elliptical galaxies. The disadvantage is that the sky becomes gaudy and unrealistic-looking.
Brightness: When a galaxy is too far away
for its image to be visible, Starry Night Pro
5.0 will represent its position in space with a dot. This slider controls the brightness of these dots. The ideal position of this slider will depend on the brightness of your monitor and the lighting conditions in your computer room. Moving this slider to the right makes the dots larger and brighter, while moving it to the left makes the dots smaller and dimmer.
you have clicked on. Some of the options specific to the Tully Collection are described below. But first lets look at some terms you may not be familiar with.
Groups are gravitationally bound clumps of galaxies. Membership can range from a few to a few thousand galaxies. Large groups are also known as clusters.
Filaments - or their kin walls, clouds, and arcs - are formations of galaxies in expanding space, which are not necessarily gravitationally bound. These formations can be string-like or sheet-like. They can have curvature like a bow or like a sail. Filaments can be grouped together into even larger structures called filament families.
Selecting Filaments and Groups in the Tully Database
When exploring the Tully Collection of galaxies, you can get more information by pointing the cursor at an object (you should see the cursor icon change to a pointer) and then right-click or Ctrl-click (Macintosh). This opens a contextual menu with specific options for the object
Centre Sun: If you are centered on another
galaxy, selecting Centre Sun will move your view so that you are looking towards the Sun (and hence our galaxy the Milky Way). If you are centered on the Sun, you can use the elevation buttons in the toolbar to go back to our solar system.
Centre Group: Each galaxy belongs to a
larger group of galaxies. This option will
Appearance of the Sky 47
place that group at the centre of your screen.
Highlight Group: This displays a special
marker for all other galaxies that are in the same group as the object you have clicked on.
Centre Filament: Many (but not all)
galaxies can also be classified as belonging to a filament. This option centres on the filament containing your object.
Highlight Filament: This displays a
special marker for all galaxies belonging to the same filament as the object you have clicked on.
Other Object Display Options
The options for other databases in Starry Night Pro 5.0 vary greatly. Open the Options dialog box for any database to see its display options.
Label Options
Every database in Starry Night Pro 5.0 has label options. To access these options, open the Options pane and click on the name of the database you are interested in. This will open the “display options” dialog box for this database. The label options will be at the bottom of the dialog box.
Most databases share the following label options:
Appearance: For all databases, you have
the option of changing the label appearance. Dropboxes allow you to change the font and size of the label, and choose whether you want the labels to be in bold or italics.
Colour: This determines the colour that
labels appear onscreen. Click on the colour bars to choose a new label colour. Many users use different label colours for each of the major databases, making it easier to quickly distinguish between planets, stars, and deep space objects.
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Number of Labels: A slider allows you to
change the number of objects that are labeled onscreen for each database. If the slider is near the left edge, only the brightest members of the database will be labeled. As you move the slider farther to the right, dimmer objects will be labeled as well.
Some other label options appear only for certain databases. These options are listed below:
Label by magnitude slider: This is an
option for planets/moons, comets, asteroids, and artificial satellites (it replaces the “Number of Labels” slider). By default, Starry Night will not label an object if it is too dim to appear on screen. You can change this option. For example, you may wish to know the position of all the planets. Pluto and Neptune are generally too dim to be seen, but by selecting this option, you will still be able to see where they are in the sky.
Constellations
People have always joined together patterns of stars to create images in the night sky. The most well known of these are those that have been handed down to us from the Arabs, Greeks, and Romans. Astronomers use these ancient constellations as a guide to map the stars into various regions. Today the International Astronomical Union recognizes 88 unique constellations, which together cover the entire sky. Many of the best-known figures in the sky, such as the Big Dipper and the Summer Triangle, are not formal constellations, but are known as
asterisms. Starry Night Pro 5.0 has many
options for drawing the constellations. All constellation options can be accessed by expanding the “Constellations” layer in the Options pane.
Star Label Options: The “Show” dropbox
in the Star Options dialog box allows you to label a star by its common name, catalogue number, Bayer letter, or Flamsteed number. Most common names are thousands of years old and have an Arabic origin. The classification scheme for Bayer letters and Flamsteed numbers is discussed in “Bayer
” on page 89. You can also choose to show the magnitude of stars, an option that is particularly useful for printed charts, as you will often use the brightness of an object to help you determine if you are looking at the right object.
Auto Identify: Checking this box will
highlight the constellation which is at the centre of the screen. If you scroll around the screen, the highlighted constellation will change.
Tip: Clicking on the words “Auto Identify” opens a dialog box that lets you choose how to display the highlighted constellations. The display options are the same as for displaying all constellations (name, boundary, stick figure or classical illustration), except they only apply to the highlighted constellation. If you choose to display an illustration, you can also control the brightness of this illustration.
Appearance of the Sky 49
Illustrations: Checking this box displays
classical illustrations for the constellations.
Labels: Checking this box turns on or off
constellation labels.
Stick Figures: Turns on or off stick figures
for the constellations.
Constellation Options: Clicking on the
words “Boundaries”, “Labels”, or “Stick Figures” will open the Constellation Options dialog box.
Boundaries: Checking this box displays
the boundaries of the 88 official constellations.
This dialog box lets you adjust the colour of the constellation figures, boundaries and labels. You can also adjust the size and font of the labels. For the labels, a dropbox lets you choose whether to display the constellation’s astronomical name, its common translation, or both. For the stick figures, you can choose from several different figure sets.
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You can draw stick figures using either the standard astronomical figures,
or those popularized by H.A. Rey in his book The Stars, a New Way to See Them. These figures closely resemble the names of the constellations. For example, Ursa Major, the Great Bear, is depicted as a stylized bear. To get the figures to match the names, Rey had to take some liberties, so it may be difficult to match these figures to what you actually see in the sky. You can also choose to draw only the constellations of the Zodiac. Finally, you can draw the asterisms, stick figures that are not formal constellations. It is also possible to create your own stick figures. See “Custom Asterisms
” on page 155 for information on creating your own figures.
Note: It is not possible to view more than one set of stick figures onscreen at the same time.
By default Starry Night shows the “Classical” image set for constellation illustrations. If you have more than one set of illustrations, you can select which one to display from the “Image set” dropbox.
Guides 1 (Co-ordinate Systems)
The Guides layer in the Options pane allows you to display reference points and grids for different astronomical co­ordinate systems. These co-ordinate systems can be used to help you locate objects in the sky. This section describes the five co-ordinate systems used in Starry Night Pro 5.0, while the next section
describes the options in the Guides layer that control the display of these co­ordinate systems.
Looking up into the night sky, you can imagine that the stars are fixed on the inside of an imaginary sphere surrounding our planet. To specify locations on this celestial sphere, astronomers use a spherical system of co-ordinates similar to the latitude and longitude measurements used to map Earth.
All spherical co-ordinate systems require two independent co-ordinates, which are determined by an object’s distance in the sky from two “great circles” which are perpendicular to each other. For example, the great circles in Earth’s latitude/ longitude co-ordinate system are the Equator (which runs east-west) and the Prime Meridian (which runs north-south).
Starry Night Pro 5.0 uses five different co­ordinate systems: alt/az, equatorial, ecliptic, galactic and extra-galactic. The most commonly used systems are the alt/az and equatorial systems.
Tip: You can find the co-ordinates of any object in any of these co-ordinate systems using the Info pane. See “Info Pane
” on
page 88 for more details.
Alt/Az: The alt/az co-ordinate system is
the most useful system for figuring out where to actually look in the sky to find a particular object. The two co-ordinates in this system are the altitude and the azimuth. The
altitude measures how high
above the horizon an object is, and is usually measured in degrees. An altitude of 0° means the object is right on the horizon, and an altitude of 90° means the
Appearance of the Sky 51
object is directly overhead. Azimuth measures the compass direction of an object. An object which is due north in the sky has an azimuth of 0°, one that is due east has an azimuth of 90°, and one that is due south has an azimuth of 180°. The
local meridian is the line passing directly
overhead in the sky that runs from 0° azimuth (due north) to 180° azimuth (due south).
Equatorial (aka Celestial): The equatorial
co-ordinate system is the most common system for describing the position of objects in the sky. Its two co-ordinates are declination and right ascension.
Declination is the astronomical equivalent
of latitude. It measures an object’s angular distance north or south of the
equator
, which is simply a projection of
celestial
Earth’s equator into space (an object of 0° declination is directly on the celestial equator). Because of this, objects with positive declination can be seen more easily in the Northern Hemisphere, and objects with negative declination can be seen more easily from the Southern Hemisphere. Declination is usually measured in degrees, arcminutes, and arcseconds (°, ', "). Polaris, the North Star, has a declination of almost 90 degrees.
The east-west measurement is called the
right ascension (RA), and is most often
measured in hours, minutes, and seconds (h, m, s), from 0 to 24 hours. Because Earth rotates, it is not possible to equate longitude on earth with right ascension. Think of lines of right ascension as longitude lines which are fixed in space, not rotating with the Earth-centred lines of longitude. The zero-point of right
ascension (RA) is defined to be the right ascension of the sun at the
Vernal Equinox,
which is the first day of spring in the Northern Hemisphere.
Earth is precessing on its axis of rotation (picture a spinning top which does not point straight up but instead moves in an arc around the vertical) with a period of 26 000 years. Because of this, the Vernal Equinox slowly changes over time and so do the equatorial co-ordinates of an object. These changes are quite small and often unimportant for the amateur astronomer. To standardize astronomical positions, astronomers often refer to an object’s position using the co-ordinate system of a particular date. For example you will often see positions given in J2000 co-ordinates, using the equatorial co-ordinate system of Jan 1, 2000. Starry Night Pro 5.0’s Info pane displays equatorial co-ordinates for the current time (JNow) and for the year 2000 (J2000).
Note: The book Starry Night Companion (included with your copy of Starry Night Pro 5.0) has more information on using the alt/az and equatorial co-ordinate systems.
Ecliptic: This reference system uses
ecliptic latitude and longitude as its two co-ordinates. Ecliptic latitude is similar to declination, except the line of 0° latitude is the
ecliptic line (a projection onto the
celestial sphere of the plane of Earth’s revolution around the Sun), instead of the plane of Earth’s equator. Notice the constellations which the ecliptic line passes through - these are the familiar zodiac constellations. The Sun will always be found directly on the ecliptic line,
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passing through the constellations of the zodiac over the course of a year. Because the planets all move in almost the same plane, with the exception of Pluto, they will all be found close to the ecliptic line. Ecliptic longitude has the vernal equinox as its zero point.
Galactic: This system uses the centre of
the Milky Way as a reference point. Its co-ordinates are galactic latitude and galactic longitude. Galactic latitude describes how far an object is from the plane of the Milky Way (an object with a galactic latitude of 0° is in the plane of the Milky Way). The zero point of galactic longitude points directly toward the galaxy’s centre.
Extra-Galactic: The co-ordinates of this
system are extra-galactic latitude and longitude. A large fraction of the nearest few thousand galaxies from Earth are concentrated in a narrow band. The centre of this band is defined as the plane of 0° extra-galactic latitude, the extra-galactic equator.
Recall that all of these options are in the “Guides” layer of the Options pane.
Axes: Displays a 3-dimensional set of
reference axes and/or a reference plane for the co-ordinate system in question. Options for changing the look of the reference axes are in the Guides Options dialog box. It is not possible to turn on reference axes for the alt/az system.
Guides 2 (Display Options)
Now that you know what each of the different co-ordinate systems are, let’s look at the options in Starry Night Pro 5.0 for displaying markers for these systems.
Equator: Displays the line of 0° “latitude”
for the co-ordinate system in question. For the alt/az system, this is the horizon line. For the equatorial system, this is the celestial equator, a projection of Earth’s equator into space. For the ecliptic system, this is the ecliptic line, a projection of the plane of Earth’s orbit around the Sun onto the celestial sphere. For the galactic system, this is the galactic equator, a line passing through the centre of the band of the Milky Way.
Grid: Displays a grid with the latitude and
longitude gridlines for the co-ordinate system in question. As you change your
Appearance of the Sky 53
field of view, the grid spacing will automatically change. You can change the default spacing of these gridlines in the Guides Options dialog box.
Meridian: Displays the line of 0°
“longitude” for the co-ordinate system in question. For the alt/az system, this is the local meridian, a line running from due north along the horizon through the zenith, through to due south along the horizon. For the equatorial system, this is the
Celestial Meridian, the line of 0° right
ascension which passes through the Vernal Equinox.
Poles: Displays markers for the points at
“latitudes” of 90° N and 90° S for the co-ordinate system in question. For the alt/ az system, these are the zenith (the point in the sky directly above your head) and the nadir (the point directly below your feet). For the equatorial system, these are projections of Earth’s north and south poles, known as the
Celestial poles
North and South
, respectively.
first day of summer (in the Northern Hemisphere), while the
Winter Solstice is
the Sun’s position relative to the stars on the first day of winter. More precisely, they are the Sun’s positions in the sky at the two exact times when the plane of Earth’s equator is inclined at the largest angle (about 23.5 degrees) to the plane determined by Earth’s revolution around the Sun.
Guides Options: Clicking on the words
“XXX Guides” in the Options pane will open the Guides Options dialog box for the co-ordinate system in question.
Vernal/Autumnal Equinox: Displays
markers for the Vernal and Autumnal Equinoxes. The
Vernal Equinox is the
Sun’s position relative to the stars on the first day of spring (in the Northern Hemisphere), while the
Autumnal Equinox
is the Sun’s position relative to the stars on the first day of fall. More precisely, they are the Sun’s positions in the sky at the two exact times when the plane of Earth’s equator is the same as the plane defined by Earth’s revolution around the Sun.
Summer/Winter Solstice: Displays
markers for the Summer and Winter Solstices. The
Summer Solstice is the
Sun’s position relative to the stars on the
You can change the colour of the markers, gridlines, and reference axes. You can also turn on/off numerical labels for the markers and gridlines.
A dropbox lets you control the spacing of the guides grid, choosing fine (lots of gridlines close together), medium, or coarse (a few lines, widely separated).
The bottom set of controls in the Guides Options dialog box affects the look of the guide axes. You can choose whether to draw just the XY grid plane, just the XYZ
54 Starry Night Pro 5.0 User’s Guide
axes, or both. Finally, you can choose to highlight the closest objects. This will give a 3-dimensional view of the position of these objects in relation to the co-ordinate system in question.
Tip: Any objects that you select (by clicking on the object) will automatically have their position highlighted on the 3-D grid.
area shown inside the indicator by Starry Night Pro 5.0 should correspond very well to what you actually see outdoors when you are observing.
In this section, you will learn how to create an equipment list which has information on all of your astronomical instruments. In the next section, “Field of View Indicators
2 (Displaying Indicators)” on page 56, you
will learn how to display FOV indicators onscreen for any of these instruments.
Opening the Equipment List: Choose
Edit->Equipment List from the main menu to open your equipment list. Initially, this list will be blank.
Field of View Indicators 1 (Creating an Equipment List)
If you own binoculars or a telescope, you may wonder how the views that you see onscreen in Starry Night Pro 5.0 match up with what you would see outdoors using your astronomical instrument. Starry Night Pro 5.0 lets you display an outline onscreen that shows the shape and field of view (FOV) of any of your astronomical instruments. We call these outlines field of view (FOV) indicators. Field of view indicators are useful because they show the exact size of the patch of sky that you will be able to see through a given astronomical instrument. Therefore, the
Types of Equipment:
The pull-down menu in the upper left corner of the equipment list displays the different types of astronomical equipment.
Appearance of the Sky 55
Some of these pieces of equipment may be unfamiliar to you.
Eyepiece. For any given telescope, you
may have several eyepieces. When viewing the same object through the same telescope, the image that you see will vary, depending on the eyepiece properties. The most important property of an eyepiece is its focal length, which affects the image magnification. Eyepieces with large focal lengths (low magnification) are good for viewing faint deep-space objects. Eyepieces with small focal lengths (high magnification) are good for viewing details on bright objects, such as the Moon or planets.
Barlow. A Barlow lens is a device that
sits between your telescope’s focuser and eyepiece. It is used to increase the magnification of an eyepiece.
Focal Reducer. A focal reducer is
essentially the opposite of a Barlow lens. It reduces the focal length of your telescope, decreasing the magnification of an eyepiece.
Finderscope. A finderscope is a
secondary telescope that attaches onto your main telescope. It has a lower magnification and a larger field of view than the main scope, and is used to locate objects in the sky, which you will then view using the main scope.
CCD. A CCD is a camera that is
attached to your telescope and used to take digital astronomical photographs.
Adding items to the equipment list: To
add your pieces of observing equipment to the equipment list, choose the appropriate equipment category (e.g. “telescopes”)
from the pull-down menu in the upper left corner of the Equipment List dialog box, then press the New button in the lower left corner. A dialog box will open, which allows you to name your piece of equipment, and enter its relevant information. You can also assign a unique colour for your indicator by clicking on the colourbar to open a colour palette. Once you have entered all of the necessary information, press the OK button to save this piece of equipment in your equipment list.
The information that can be entered depends on the type of observing equipment. All of the necessary information should be available in the documentation that came with your equipment. Some of this information is used by Starry Night Pro 5.0 when it calculates how the field of view indicator will look when drawn onscreen.
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The following information fields need to be correct:
Te le sc op e: aperture, f/stop Eyepiece: focal length, apparent field of
view
Barlow: magnification factor Focal reducer: reduction factor CCD: imaging area, camera roll angle Binoculars: measure of width or angular
field of view
Editing the equipment list: To modify the
details of any piece of equipment, open the Equipment List, click on the appropriate piece of equipment, then click the Edit button. A dialog box will open, allowing you to modify any details.
Deleting an item from the equipment list:
To remove an item from your equipment list, open the equipment list, click on the appropriate piece of equipment, then click the Delete button.
telescopes, finderscopes and binoculars. The list will include all of the telescope eyepieces, CCD cameras, finderscopes and binoculars that you added when you created your equipment list (see “Field of
View Indicators 1 (Creating an Equipment List)” on page 54 for information on
creating an equipment list). If you have not yet created an equipment list, the list of FOV indicators will also be blank.
The name of each indicator and its field of view are shown. The colour of the indicator is displayed to the right of its name.
Shop Online: Pressing this button will
connect you to a website with options to purchase astronomical equipment.
Field of View Indicators 2 (Displaying Indicators)
The FOV side pane allows you to display an outline onscreen
that shows the shape and field of view (FOV) of any of your astronomical instruments. You can also create special indicators that highlight specific objects or areas of the sky.
Indicator List: To see the list of FOV
Indicators, open the FOV pane. You will see a list of indicators, divided into
Turning indicators on/off: Checking/
unchecking the box to the left of the indicator name turns on/off the outline for that indicator. For telescopes (except finderscopes), you need to check a specific eyepiece or CCD, not the telescope itself.
After you have turned an indicator on, you should see the indicator in the main Starry Night Pro 5.0 sky view at the centre of the
screen.
Multiple Indicators: You can turn on more
than one FOV indicator at a time. You may wish to make each indicator a different colour to make them easier to distinguish. One situation where you might wish to
Appearance of the Sky 57
display indicators is if you are using a primary telescope and a finderscope.
Tip: To change the colour of an FOV indicator, just click on the colourbar to the right of the indicator name in the FOV pane.
Adding a Barlow/Focal Reducer: For your
telescope eyepieces or CCD cameras, the size of the field of view indicator will change if you are using a Barlow lens or a focal reducer.
To turn on/off a Barlow lens or focal reducer for given eyepiece or CCD camera, click the area to the right of the indicator’s name in the FOV pane. Any Barlow lenses or focal reducers that you added to your equipment list will appear in a pull-down menu. Select the appropriate option from the menu.
To add one of these indicators, click the
Add button in the Other (All Charts) or Other (This Chart) layer in the FOV pane.
The difference between these two layers is that indicators added to Other (This Chart) will automatically disappear from your list of indicators when you adjust the sky view in Starry Night Pro 5.0. This is handy if you want to add indicators only to create a specific image, as you will not need to go to the trouble of deleting these indicators after you have created the image.
Once you press the Add button, a dialog box opens that allows you to specify the properties for your new indicator. You can choose a name, colour, and field of view for the indicator. Unlike FOV indicators that are associated with an item from your Equipment List (which are automatically centred onscreen), you can also specify the indicator position.
You should see the size of the onscreen indicator change when you turn on or off a Barlow lens or focal reducer.
Adding other indicators: It is possible to
display FOV indicators that do not correspond to any of the items in your equipment list. You may wish to do this to highlight specific objects on your screen view or printed charts.
There are three ways to enter an indicator position:
Relative to screen centre: Your indicator will be at a certain offset from the screen centre. The offset is determined by the values that you enter for “Delta H” and “Delta V”. “Delta H”
58 Starry Night Pro 5.0 User’s Guide
is the horizontal offset and Delta V is the vertical offset (both in pixels). An indicator with an offset of (0,0) would be directly at the centre of the screen.
RA/Dec: This keeps your indicator centred on a specific right ascension and declination on the celestial sphere.
Alt/Az: This keeps your indicator centred on a specific altitude and azimuth, relative to your local horizon and direction.
Tip: If you want to centre your indicator on a specific object or area of sky, right­click (Ctrl-click on the Mac) on the object or area of sky and choose Add FOV Indicator from the contextual menu that pops up. Choose an RA/Dec position or Alt/Az position. The default co-ordinates for this indicator will be centred on the object or area of sky in question.
There are several cases where adding specially positioned indicators might come in handy. For example, assume you want to create a star chart that shows you how to “star-hop” from a bright deep space object to a more obscure object. You could add multiple indicators to your Starry Night Pro 5.0 view (and printed chart), tracing out the path that you would need to follow.
Deleting indicators: You can delete any of
your Field of View indicators by double­clicking on the indicator’s name in the FOV pane, then clicking the Delete button in the dialog box that opens.
Flip
Another way of modifying Starry Night Pro 5.0’s screen appearance to
match your telescope is to flip your view. You can flip your view horizontally, vertically, or in both directions, to match what you see through your telescope. You flip your view by choosing Options->Flip from the menu. You can then print out charts that match the telescope’s view and use those charts during observing sessions. If you observe the sky with binoculars or the naked eye, you will not need to use this option.
Heads-Up Display (HUD) Options
In “Identifying Objects In The Sky
” on page 21, you learned that pointing the cursor at an object onscreen causes Starry Night Pro 5.0 to display the object’s name, constellation and distance. This feature is known as the Heads-Up Display (HUD). You can change the look of the HUD and also change the information fields that it displays, by choosing Preferences from the File menu (Windows) or the Starry Night Pro 5.0 menu (Macintosh) and selecting Cursor Tracking (HUD) from the dropbox in the top left corner of the Preferences dialog box.
You can set the HUD to display information only when you are holding down a certain key. This is useful if you find that the HUD information appears too frequently and gets in your way. You can also avoid this problem by moving the “Mouse is idle for...” slider farther to the right. This slider controls how long the cursor must be pointing at an object before the HUD information is displayed.
Appearance of the Sky 59
these information fields. If you wish, you can draw each piece of information in the HUD with a different colour.
Finally, you can choose the font, style, and size of the text in which the HUD information is displayed.
Tip: You can choose to display the HUD information on the upper left side of the screen instead of directly beneath the object, by checking the “Show info in upper left corner of screen” box.
OpenGL Options
OpenGL offers improved graphics on computers whose video hardware supports it. You can access the OpenGL preferences by choosing Preferences from the File menu (Windows) or the Starry Night Pro
5.0 menu (Macintosh) and selecting OpenGL from the dropbox in the upper left corner of the Preferences dialog box.The OpenGL dialog box allows you to select a number of options.
Unchecking the “Show info only when over an object” option causes the HUD information to appear even when you point the cursor at the black background sky. This can be useful in determining the co-ordinates of any position in the sky.
A long list of information fields gives you control over which object information is displayed, including name, magnitude, distance, and so on. You can also choose the colour in which you want to display
60 Starry Night Pro 5.0 User’s Guide
Cross fade slider: Rather than jumping
straight into a new scene, instantly load a new Starry Night File (SNF) or label an object, you can add a fade ‘break’ between actions that change your sky view. Think of it as the fade-in/fade-out effect between images in a photo slideshow. Use this slider to control the cross fade transition timing between actions in Starry Night Pro
5.0.
Use OpenGL: Checking this option will enable OpenGL if your video card supports it. If for some reason, you have an OpenGL graphics card but do not wish to run the OpenGL version of Starry Night, uncheck this box.
Use sub-pixel accuracy when plotting labels: Sub-pixel accuracy gives labels a
smooth feel as they move on the screen. However, depending on your video card, this can cause labels to flicker.
Draw stars using polygon smoothing: Some video cards have trouble doing what's called polygon smoothing and this can cause "blocky stars". By default, polygon smoothed stars are turned off on the PC and turned on on the Mac. If you are experiencing the "blocky star" effect on the Mac you can try turning this feature off. On the PC, if your card supports it, turning this feature on can improve the speed at which stars are drawn; if your card doesn't support it, it can result in stars being drawn slower or having a blocky appearance.
Show specular reflection on planet surfaces: Realistically models the Sun’s
glare on planet surfaces.
Use prespective correction when showing planet surfaces: Corrects for
prespective when viewing planet surfaces.
Use half size textures: Checking this option will save on video graphics memory and should improve performance on slower computers or video cards with less than 32 MB of memory.
Force texture cache size: Specifies the amount of memory cached by your video card.
Tip: If you set the texture cache to only 16 MB, it automatically sets the “use half size textures” option.
Number Formats
You can change the number format for the information displayed by the HUD by choosing Preferences from the File menu (Windows) or the Starry Night Pro 5.0 menu (Macintosh) and choosing Number Formats from the dropbox in the upper left corner of the Preferences dialog box.
There are a number of different formats in which declination, altitude, right ascension, and azimuth can be displayed, and you can choose appropriate formats
Appearance of the Sky 61
for each of these options using the dropboxes.
•d: degrees
•m: minutes
•s: seconds
The number of occurrences of each letter indicates the number of decimal places. For example, “dd mm.mmm” indicates that degrees will be displayed by up to two digits, with minutes being displayed by up to two digits rounded off to three decimal places — 25° 30.123'.
For distances, you can choose to view the distance between you and any celestial object in either light years or parsecs. One
parsec is equal to about 3.26 light years.
White Sky Mode
You learned how to print star charts in “Printing Star Charts
” on page 27. Starry Night Pro 5.0 also allows you to simulate printed starcharts on your screen, by choosing Options->White Sky from the menu. This displays a negative image of your Starry Night Pro 5.0 view, reversing the colours of objects and labels. Stars are represented by dark circles on a white background.
Note: Options->White Sky differs from Options->Presets->Print Settings because it
does not use Starry Night Pro 5.0’s special print settings, it just displays a negative image using your existing settings.
Night Vision Mode
Selecting Night Vision from the Options menu instructs your monitor to dim its display red. Night Vision mode is suitable for outdoor, night-time viewing, as it helps to preserve dark adaptation when you look into your computer’s display.
62 Starry Night Pro 5.0 User’s Guide
Because of the control Night Vision must exert over your computer display, not all computers will support it.
Adjusting brightness: You can adjust the
brightness of night vision mode by choosing Preferences from the File menu (Windows) or the Starry Night Pro 5.0 menu (Macintosh), selecting Brightness/Contrast from the dropbox in the upper left corner of the Preferences dialog box, and adjusting the Night Vision slider in this dialog box.
Turning night vision off: If you are in
Night Vision mode, choose Options->Night Vision from the menu to turn night vision off.
Full Screen Mode
Starry Night Pro 5.0 has two menu options that allow you to hide the screen controls. Selecting View->Hide All Controls will hide the side panes, the toolbar, and the button bar (Windows only). Selecting View->Fullscreen hides the main menu, the scrollbars, and the window frame. By using these two options together, you hide all controls and menus, for a full screen view of the sky. Even with all controls turned off, you can still move around the sky using the many keyboard shortcuts available, such as the arrow keys. For a complete list of shortcuts, see “Keyboard Shortcuts
” on page 171.
Tip: Once you are in full screen mode, you will need to find your way back out! Press the F7 key to restore the main menu, and then choose View->Show All Controls to restore the other controls.
Saving Your Settings
Now that you know all of the features for adjusting the appearance of the sky, you may wish to make some changes to Starry Night Pro 5.0’s default settings. For example, you may want Starry Night Pro
5.0 to always open with daylight turned off. Choosing Options->Save Current Options as Default will save all of your appearance settings so that Starry Night Pro 5.0 will use these settings whenever you start the program or open a new window. This allows you to set up Starry Night Pro 5.0 to look exactly the way you like, every time you use the program.
Restoring Default Settings. Choosing
Options->Presets->Default will restore all of the settings in Starry Night Pro 5.0 to the default values you have chosen (or the built-in default settings, if you have never used the Save Current Options as Default option).
Multiple Settings: You may wish to create
a set of appearance settings that is not used as the default. To do this, set Starry Night Pro 5.0 up the way that you want, then choose Options->Save Preset... from the menu. This will open a dialog box that allows you to name your new settings files. Any settings files that you create can then be turned on from the Options->Presets menu.
Customizing Print Settings: You may wish
to modify Starry Night Pro 5.0’s default print settings. To do this, first apply the default print settings by choosing Options->Presets->Print Settings from the menu. Next, make any changes to these settings. Finally,. choose Save Preset... from the Options menu and click on the
file “Print Settings.sno” in the Save dialog box that opens. This will replace Starry Night Pro 5.0’s default print settings with your own.
Global Preferences. Certain aspects of
Starry Night Pro 5.0 are treated differently than your appearance settings (which you save by choosing Options->Save Current Options as Default). These aspects are called global preferences. When you change a global preference, the change will be saved automatically (there is no need to choose
Options-> Save Current Options as Default). All of the options in the Preferences menu are global preferences.
Tip: You can restore the global preferences which initially accompanied Starry Night Pro 5.0 by choosing Preferences from the File menu (Windows) or the Starry Night Pro 5.0 menu (Macintosh) and pressing the Factory Defaults button in the Preferences dialog box.
Appearance of the Sky 63
64 Starry Night Pro 5.0 User’s Guide
Chapter 4
Sky Data
This chapter will show you how to use several different Starry Night Pro 5.0 features and functions that teach you more about the night sky and give you more information about astronomical events and the sky in general. In the next chapter, “Object Databases will learn how to access information about specific objects.
Note: Some of the features in this chapter require an Internet connection. If you are not connected to the Internet when you try to access these features, Starry Night Pro 5.0 will try to connect you. If you do not have Internet access, you will not be able to make use of these features. All of the features in the LiveSky menu require an Internet connection. If you are using a feature that requires downloading information from the Internet, and the download is going too slow, you can choose LiveSky->Stop Downloads to abort the download.
” on page 77, you
66 Starry Night Pro 5.0 User’s Guide
SkyGuide
Dozens of interactive multimedia tours await you in the SkyGuide pane. These in­depth experiences reveal the fascinating science and history of the solar system, the stars, the galaxies, the beginning of time, and the fate of the universe. It also includes daily headline news on astronomy and step-by-step instructions on how to use the most common Starry Night Pro 5.0 features.
There’s no interface to learn: it works just like a web browser!
As you and SkyGuide explore together, you will learn tips for navigating the sky, fun facts of the solar system, seasonal tours of the sky, and much, much more. Throughout this multimedia matrix you’ll discover images and movies to enhance the experience.
This section highlights some of the main features in SkyGuide.
Click on the tab named SkyGuide to open the
SkyGuide panel.
From the home SkyGuide page you can select five main options:
Weekly sky events: Takes you to a listing
of all the major celestial events for the upcoming week.
Daily headline news: The latest astron-
omy and hobby news. This is a page devoted to amateur astronomers and space enthusiasts, written by professional space journalists. It is updated daily and has lots of skywatching tips, plus topical stories on astronomical events (new comets, meteor showers, planet conjunctions, and much more). Many of the stories are illustrated with graphics created with Starry Night Pro 5.0. An internet connection is required to view this content.
Enter SkyGuide: Begin your exploration of
the night sky here. This link will take you to dozens of interactive tours - your pass­port to a voyage through the universe.
Starry Night features: Highlights the
main features of your program. We highly recommend that you read through this sec­tion.
Starry Night basics: Review the basic
controls and functions in Starry Night Pro
5.0.
To start exploring the main SkyGuide con­tent, select the Enter SkyGuide link. The SkyGuide menu is divided into seven
Sky Data 67
major categories:
Welcome Tour: A self-running guided
introduction to Starry Night and the things you can do.
Quick Find: Find a planet, star, constella-
tion and other interesting objects. These lists of objects are usually organized by season, letting you know when they can be best observed.
First Night Out: An introduction to the
night sky and how to navigate your way around.
Night Sky Tours: Guided tours of selected
objects in the night sky. Take a seasonal tour of the night sky or explore the images taken by space observatories.
Our Solar System, the stars and our gal­axy:
An introduction to objects in our solar system and beyond. This section tells you what to look for and how to locate them in the night sky.
SkyCalendar
The SkyCalendar is your portal to weekly astronomical events, solar and lunar eclipses, Moon phases, regional star par­ties and observation logs. You can also import, view and even create your own calendars (using the standard vCalendar format). For example, you can create a cal­endar of local events and share them with other members in your club. See “Adding
Calendar Events” on page 137 for instruc-
tions on adding your own events to the SkyCalendar.
To open the SkyCalendar, click on the SkyCalen-
dar side pane.
Record holders: What is the largest planet
in our solar system? Which one is the hot­test? Find out the answers in record hold­ers.
Dictionary: A list of the most common
astronomical terms.
We suggest you start with the Welcom e Tou r and then explore the other sections of SkyGuide. Have fun browsing!
68 Starry Night Pro 5.0 User’s Guide
At the top of the SkyCalendar pane is a window that lists all the event calendars. At the bottom of the pane is a monthly cal­endar with Moon phase information. Between the list of calendars and the Moon phase calendar is the description fields for an event.
Viewing a calendar event: The calendar
events window lists the calendars that come with Starry Night Pro 5.0. Each cal­endar has a name such as Lunar & Solar Eclipse or Upcoming Events.
You can click on the info icon to the right of each calendar name to learn
more about that calendar.
To view a calendar event for any of
the calendars listed, click on the expand icon to the left of the calendar name. This will display a chronological listing of all the events for that calendar. Clicking on an event will highlight it and display the details and other options for the event.
Note: Calendar events are updated frequently. To download the latest event data available select LiveSky->Update Comets/Asteroids/Satellites from the main menu.
Each event contains the following infor­mation fields.
URL: An Internet link with additional information about the event.
Description: A detailed description of the event.
Depending on which calendar event you select, you may see one of the following control buttons.
Web : An option when viewing an upcom­ing event. If an Internet link with addi­tional information about the event is available, you can click on this button to open your web browser.
View Event: An option when viewing an upcoming event. Clicking this button will display the celestial event on the main sky window.
Home View: An option when viewing lunar and solar eclipse events. Places you at the event time looking in the proper direction, as seen from your home loca­tion. If the event is not visible at all from your location at this time, this option is grayed out.
Best View: An option when viewing lunar and solar eclipse events. Places you at the best time and place to watch the event. For example, selecting Best View for a solar eclipse places you on the surface of the Moon.
Event name: The name of the calendar event.
Start/Finish: The start and finish times for the event.
Location: The location of the event.
Edit Log: An option when viewing log events. Allows you to edit your log entry and make changes.
Centre Target: An option when viewing log events. This adjusts your view so that the object in your log is placed in the cen­tre of the screen.
Sky Data 69
By default Starry Night Pro 5.0 lists all calendar events. You can also select to only display events for this week, this month, this year or even just past events. To
customize the events shown in the calendar window, select an option from the dropbox on the upper left of the SkyCalendar pane.
Searching for an event: If you are inter-
ested in finding a specific event, such as a lunar eclipse or an occultation, click on the dropbox on the upper left of the SkyCalen­dar pane and select one of the find options in the menu. You can select to search for events that contain, begin with or end with. If you want to exclude a class of events, select not containing.
date. To enable this option, you must first select "Set current view to date" from the dropbox menu at the bottom of the Moon phase calendar. You can also have the cal­endar window show only the events for the date you clicked on in the Moon phase cal­endar. To enable this option, select "For dates selected in calendar" from the drop­box menu at the top of the SkyCalendar pane.
Tip: You can select multiple dates on the Moon phase calendar by holding down the Shift key on your keyboard when clicking on subsequent dates.
Calendar icons: Some dates on the Moon
phase calendar will have small icons. These icons are there to let you know of any events happening on that date.
The log icon lets you know you have a log entry for that date.
The telescope icon symbolizes a star party.
Browsing events with the Moon phase cal­endar:
The Moon phase calendar offer a quick way to glance at Moon phase infor­mation for any month of the year. To change the month and year displayed on the moon phase calendar, use the year and date buttons immediately above the Moon phase calendar.
You can click on a date you are interested in on the moon calendar, and the date in Starry Night Pro 5.0 will switch to that
The star icon represents an upcoming or interesting celestial event.
You can toggle the icons displayed on the Moon phase calendar on and off by using the checkbox to the left of a calendar's name in the calendar window.
Lunar & Solar Events Calendar: The
events in this calendar fall into several dif­ferent categories you might not be familiar with.
Total Solar Eclipse: : An eclipse of the Sun
where the Moon completely covers the Sun.
70 Starry Night Pro 5.0 User’s Guide
Annular Solar Eclipse: An eclipse of the
Sun where the Moon passes directly in front of the Sun, but does not completely cover it. At the eclipse's peak, a ring of sunlight still shines around the Moon's edges.
Partial Solar Eclipse: An eclipse of the
Sun where the Moon covers only part of the Sun. The sky does not darken notice­ably during a partial eclipse.
Total Lunar Eclipse: An eclipse of the
Moon where Earth crosses between the Sun and Moon, blocking sunlight from reaching any of the Moon's surface. Dur­ing a total eclipse, the Moon darkens slightly and takes on a reddish colour.
Umbral Lunar Eclipse: An eclipse of the
Moon where Earth crosses between the Sun and Moon, blocking sunlight from reaching only part of the Moon's surface. This part will appear darker than the rest of the Moon.
Penumbral Solar Eclipse: An eclipse of
the Moon where Earth crosses between the Sun and Moon, but only partially blocks the Sun's light. Because some light still reaches all parts of the Moon, the Moon does not darken noticeably during a pen­umbral eclipse.
Tip: If an eclipse is not visible from your location, select Best View to view from the Moon. Zoom in to see which areas of Earth are seeing a partial eclipse (anywhere inside the large shadow) and which areas are seeing a total eclipse (anywhere inside the tiny circle in the middle of the shadowed area). Then stop time, right-click the mouse (Ctrl-click on the Mac) on an area inside the smaller circle, and click Go There from the popup menu. This will change your location to the exact spot on Earth where you clicked the mouse, so you can watch the eclipse from Earth.
DVD Movies
Note: The list of Lunar & Solar Events is not customized for each location on Earth. This means that not every event listed will be visible from your location. A total solar eclipse, for example, may appear as a partial eclipse from your location, or may not be visible at all. Use Starry Night Pro
5.0 to help you find out if an event is visible from your location.
Over an hour of multimedia videos are included with Starry Night Pro 5.0 on a separate standalone DVD - “SkyTheater”. These videos explore topics that range across the entire field of astronomy, from observing satellites to hunting comets. The videos will help you learn more about astronomy, and will increase your enjoyment of Starry Night Pro 5.0.
Sky Data 71
LiveSky Pane
Although Starry Night Pro 5.0 has a wealth of built-in astronomical information, much more information exists on the Internet. LiveSky is a gateway to the rich resources of the Internet. You can use LiveSky to locate information on the Internet for any object, or to access live, up-to-the minute data and images for certain celestial phenomena. This section shows you how to use LiveSky to access live images for celestial phenomena. “LiveSky.com Object Database
” on page 94 will show you how to use LiveSky to locate Internet information for specific objects.
Open the Livesky side pane to access live images.
information about the image, such as its source and date. Beneath the image information are two buttons.
Clicking this button opens the image in a new, larger,
window.
Clicking this button causes Starry Night Pro
5.0 to begin downloading an up-to-date image from the Internet.
Accessing Images: You choose which
image will be displayed in the LiveSky pane by expanding one of the layers listed beneath the image, and then clicking on an image name.
At the top of the open LiveSky pane will be an image. Beneath the image is
Clicking on an image name will display the most recently downloaded version of this image. It will not attempt to download an up-to-date version of the image - you need to press the Refresh button to do this.
Clicking the information icon to the right of an image name will display a
brief description of the image.
Types of Images: LiveSky can provide
you with up-to-date images of many different celestial phenomena: images of the Sun as seen through different filters and at different wavelengths, plots of the sun’s electromagnetic activity, images of
72 Starry Night Pro 5.0 User’s Guide
auroral activity (northern and southern lights) in Earth’s atmosphere, and satellite imagery of Earth. As more types of live planetary images become available online, links to these images will be added to LiveSky.
Status Info
The Status side pane provides a handy summary
of all of the general information about your sky view - for example, your viewing location, time, and viewing direction. All of the information in the Status pane is dynamic - if you change your view onscreen (for example, by changing your time or viewing direction), the fields in the Status pane will automatically update to reflect the new view.
The information displayed falls into four areas: general information, time information, location information, and a Hertzsprung-Russell diagram.
Note: Some of the fields in the Status pane are only useful to specialists. These fields are marked with three asterisks (***) and you should feel free to skip over the descriptions of these fields.
1 General Information:
Export: Clicking the Save Info button will
export the information in the Status pane to a text file.
Looking: The direction in which you are
viewing. Both the distance from the horizon and the compass direction are listed.
Field of View: The exact width and height
of your current field of view.
Limiting Magnitude: The magnitude of the
dimmest object visible in your current view. Magnitude is a measure of the brightness of objects and is discussed in
Magnitude
” on page 91. As you zoom in
to smaller fields of view, Starry Night Pro
5.0 automatically shows dimmer objects, or in other words, increases the limiting magnitude.
2 Tim e:
Sky Data 73
Universal Time: This field displays the Universal Time of your current view.
Because of time zones, an astronomical event (such as a lunar occultation) could take place at any of 24 different times, depending on your location. To avoid confusion, astronomers often report event times using a standard time known as
Universal Time, which is the same
everywhere in the world. Universal time is equal to the local time in Greenwich, England (without Daylight Saving Time), 5 hours ahead of Eastern Standard Time.
Local Time: The local time of your current
view.
***Julian Day: The Julian Day is another
astronomical time concept, used by astronomers to avoid the problems resulting from historical calendar changes. The Julian Day is simply the number of days that have elapsed since noon, January 1, 4713 B.C. Fractions of days are given in decimal values. For example, the Julian day 2451544.5 is 2 451 544 days and 12 hours after noon, January 1, 4713 B.C., which happens to be midnight on Dec. 31, 1999!
ascension equal to the sidereal time are crossing the local meridian at their highest point in the sky, and this is often the best time to observe the object.
***Delta T: Delta T measures the
difference between terrestrial time (aka ephemeris time) and Universal time. Historians use delta T to date historical events precisely using solar eclipses.
3 Location:
Location: The name of your current
viewing location (usually a city name).
Latitude/Longitude: The latitude and
longitude of your current viewing location.
Tip: If you want to set the date in Starry Night Pro 5.0 to a specific Julian day, open the pull-down menu to the immediate right of the date/time display in the toolbar and choose Set Julian Day from the menu.
***Sidereal Time: The local sidereal time
of your current view, which ranges from 0 hours to 24 hours. Sidereal time measures the rotation of Earth with respect to the background stars, not the Sun. A sidereal day is about 4 minutes shorter than a solar day. Astronomers find sidereal time helpful because objects with a right
***Heliocentric X, Y, Z: Heliocentric
co-ordinates reference your position in space with respect to the Sun. Heliocentric co-ordinates of (0, 0, 0) would place you at the center of the Sun. The X and Y co-ordinates mark your position along the ecliptic plane (the plane of Earth’s orbit around the Sun). The Z co-ordinate indicates your distance from the ecliptic plane. Earth travels along the ecliptic plane, so if you are on Earth’s surface, your heliocentric Z value will be close to
0. Heliocentric co-ordinates are given in
astronomical units (AU’s). 1 AU is the
74 Starry Night Pro 5.0 User’s Guide
average distance between Earth and the Sun, about 150 000 000 km.
***Distance from Sun/Angle from Ecliptic Plane/Phi:
Another set of heliocentric co-ordinates, using angular measures instead of X, Y, Z co-ordinates. Phi specifies the angle along the ecliptic plane, with the zero point being the position of Earth on the autumnal equinox.
4 Hertzsprung-Russell:
Expand the Hertzsprung-Russell layer to view a special kind of graph known as an
H-R (Hertzsprung-Russell) diagram.
the upper right corner of the H-R diagram. Finally, “white dwarf” stars will be found along the bottom left of the H-R diagram, beneath the main sequence.
The stars plotted in the H-R diagram are the same stars shown onscreen in the main window. You can click on any star in the H-R diagram, and Starry Night Pro 5.0 will draw a circle around this star on the main window, allowing you to identify it. This makes it easy to identify stellar oddballs, such as white dwarfs, supergiants, and extremely massive main sequence stars. Conversely, you can point the cursor at any star in the main window, and Starry Night Pro 5.0 will highlight this star’s position (with a red dot) on the H-R diagram.
Tip: The H-R diagram is fully dynamic. If you scroll around the screen or change your field of view, the stars shown onscreen will change, and the H-R diagram will update to plot these new stars.
An H-R diagram tells us about a star’s age and its mass. Each dot on the diagram represents a star. The diagram plots star luminosity (amount of light & energy emitted by the star) on the vertical axis versus star temperature on the horizontal axis. Young stars which are still burning hydrogen in their cores are found in the “Main Sequence”, the curve along the left side of the graph. The larger and heavier a star is, the farther it will be to the upper left along this curve. Older stars in the “red giant” phase of their life are no longer on the main sequence, and will be found in
H-R Diagram Options:
Expand the H-R Options layer beneath the H-R diagram to access options that affect the appearance of the diagram.
Use Absolute Magnitudes: Unchecking
this option will plot apparent magnitude
Sky Data 75
instead of absolute magnitude on the vertical axis.
Automatic ranges: Checking this option
will cause Starry Night Pro 5.0 to select the smallest possible ranges for the X and Y axes that still manages to include all stars visible onscreen.
Image Brightness: This slider controls
how bright the star dots in the H-R diagram are drawn.
Distance Cut-Off: This plots only those
stars with distances from Earth that lie between the minimum and maximum distances that you specify.
Labels: Unchecking this option draws a
blank graph with no labels. Checking this option allows you to turn on any of the label options listed below.
Gridlines: Draws gridlines from the
vertical and horizontal axes.
B-V: Uses a stars B-V colour as the field
along the horizontal axis. Hotter stars have a lower B-V value.
Kelvin X 1000: Plots star temperature (in
thousands of degrees Kelvin) along the horizontal axis. Degrees Kelvin are equal to degrees Celsius + 273.
Spectral Class: Plots star spectral class
along the horizontal axis.
Main Sequence: Draws a line representing
stars on the main sequence. Any star that appears close to this line is probably a main sequence star (a star that is still burning hydrogen fuel).
Regions: Labels the areas of red giants,
white dwarfs, and main sequence stars.
Note: White dwarfs are very dim and few are in Starry Night Pro 5.0’s star catalogues (the Hipparcos/Tycho-2 catalogues), so few will be found in Starry Night Pro 5.0’s H-R diagrams.
Dim Labels: Draws the diagram labels
much dimmer than the stars.
Downloading Photographic Images
Starry Night Pro 5.0 shows over 17 million celestial objects, but this is only a tiny fraction of the stars and objects that can be seen from Earth using telescopes.
On the Internet, the Space Telescope Science Institute (STScI) hosts a very large database, called the Digitized Sky Survey (DSS). This survey contains large, high-resolution pictures of the entire night sky. The database is so large that it is distributed on a few hundred CD-ROMs. Starry Night Pro 5.0 makes it easy to look at the thousands of galaxies, nebulae, and other astronomical phenomena that are contained in this database.
The STScI offers an online form you can fill out to request a picture of the sky. Starry Night Pro 5.0 makes this process considerably easier. Just zoom in on the part of the sky that you want an image of, and select LiveSky->Show Photographic Image.
Getting a picture from the Digitized Sky Survey to your browser can take up to a few minutes, so you have to be patient. The reason for the delay is that the Digitized Sky Survey’s computer has to
76 Starry Night Pro 5.0 User’s Guide
assemble your request from its extensive database.
Tip: You can only download Digitized Sky Survey images when your field of view is between about 1.5 arcminutes and 30 arcminutes. If your field of view is outside this range, this menu item will appear greyed out.
Example: Viewing the Horsehead Nebula using the Digitized Sky Survey.
1Open the “horsehead”. Starry Night Pro 5.0 should list the Horsehead Nebula.
2 Double-click on the Horsehead Nebula’s entry in the list, to centre on this object.
3 Now use the zoom buttons in the tool­bar to zoom in to a field of view of about 20' (20 arcminutes), so that the Horsehead Nebula almost fills the screen.
4Choose
Find pane and type in
LiveSky->Show Photographic Image to
obtain an image of the Horsehead Nebula from the Digitized Sky Survey. The new image will open in your web browser.
Tip: After you have loaded an image from the Digitized Sky Survey, you can paste it in Starry Night Pro, and it will remain there every time you run the program. For more information, refer to “Adding
Images from the Digitized Sky Survey” on
page 150.
Online Telescope Imaging
The Digitized Sky Survey allows you to download images of any section of the sky from an image database. These images are several years old. Another feature actually allows you to capture live photographic images of the sky, by directing a remote telescope and camera over the Internet! Unlike any of the other features in Starry Night Pro 5.0, a small fee is charged to capture images.
Selecting LiveSky->Online Telescope Imaging from the main menu will open a web page with instructions on requesting photographic images.
In this example, we used the Digitized Sky Survey to load an image of an object which Starry Night Pro 5.0 already had an image for. You would be more likely to use the Digitized Sky Survey to download images of areas of the sky for which Starry Night Pro 5.0 does not have a detailed image. One way to explore with the Digitized Sky Survey is to turn on the NGC/IC database or the Galaxies database and look for an interesting cluster of galaxies. Zoom in on a promising cluster and then request the Digitized Sky Survey image for a detailed view.
Chapter 5
Object Databases
This chapter will show you how to learn more about galaxies, meteor showers, planets, and all of the other marvelous denizens of the night sky. You will first learn about all of the different object databases included in Starry Night Pro 5.0. Next, you will learn how to get more information about any of the objects in these databases.
Note: Some of the features in this section require an Internet connection. If you are not connected to the Internet when you try to access these features, Starry Night Pro 5.0 will try to connect you. If you do not have Internet access, you will not be able to make use of these features. All of the features in the LiveSky menu require an Internet connection. If you are using a feature that requires downloading information from the Internet, and the download is going too slow, you can choose LiveSky->Stop Downloads to abort the download.
78 Starry Night Pro 5.0 User’s Guide
Introduction to Databases
Starry Night Pro 5.0 includes literally millions of celestial objects, from dozens of different databases.
Accessing Databases: As you learned in
chapter 3, “Appearance of the Sky
”, you
can use the Options side pane to turn databases on/off, turn their labels on/off, or modify the database display options. All of these functions can also be accessed from the main menu, by choosing View, Labels, or Options, respectively.
We’ll now briefly describe each of the databases included in Starry Night Pro 5.0. The databases in your version of Starry Night Pro 5.0 may be slightly different from those listed here, as we are continually updating and adding new databases. As you learned in “Options Pane
” on page 32, databases are organized in a layered framework, based on their distance from Earth.
The three major database layers are:
1 Solar System
2 Stars
much more rapidly than Earth rotates, so they move over a large slice of the Earth’s surface. Geosynchronous satellites are much farther from Earth. They move at exactly the same speed as Earth rotates, so they stay directly above the same point on Earth’s surface at all times. Starry Night Pro 5.0 includes about 150 satellites. Satellite data needs to be updated regularly. See “Database Updates
” on page 83 for information on updating satellite data.
Meteor Showers: This database marks the
positions of the major meteor shower
radiants. The radiant is the point in the sky
where all meteors from a given meteor shower appear to be coming from. Meteor showers are formed by comets that come close to the Sun. Heat from the Sun causes dust and rock to break off the comet and gather into a collection of debris that moves along the comet’s orbital path. If Earth’s orbit crosses this path, there is a meteor shower as the dust particles burn up in Earth’s atmosphere. Each meteor shower happens at about the same time each year. This database uses data from the International Meteor Organization and was created by Stephen Hutson.
3 Deep Space
Databases 1 (Solar System)
These databases are for objects that are inside our solar system.
Satellites: This refers to any man-made
body orbiting our Earth. Most satellites fall into two distinct types of orbits:
near-Earth orbits or geosynchronous orbits. Satellites in near-Earth orbit move
Asteroids: Small, rocky bodies that are too
small to be planets. Most asteroids lie in the “asteroid belt”, a region of space between the orbits of Mars and Jupiter. Asteroid data needs to be updated regularly. See “Database Updates
” on page 83 for information on updating asteroid data.
Comets: These are the small balls of rock
and ice which revolve around the sun. Comets have very elliptical orbits, meaning their distance from the sun varies
Object Databases 79
greatly with time. Comets are usually far away from the Sun, out beyond the orbit of Pluto, too dim to see. Once in a long while, they come close to Earth and the Sun, picking up speed and getting brighter. Starry Night Pro 5.0 includes about 150 comets, including some great comets of yesteryear such as Halley and Hale-Bopp. Comet data needs to be updated regularly, so that any bright new comets are added to Starry Night Pro 5.0’s database. See “Database Updates
” on page 83 for
information on updating comet data.
Planets/Moons: The Sun, the nine major
planets that orbit the Sun, and all of the moons of these planets. In the past few years, many new small moons have been discovered around the outer planets. Starry Night Pro 5.0 includes all of the moons that were known at the time of release. If any new moons are discovered in the future, data for these moons will be available on our website. Choose View->Check For Program Updates to see if any new data is available.
Databases 2 (Stars)
This includes not only stars, but all objects that are outside of our solar system, but still inside our galaxy, the Milky Way.
Milky Way: The band of our Milky Way,
which stretches across the night sky. The misty band of illumination that we see is actually the combined light of millions of stars. It is possible to adjust the brightness of the Milky Way.
Pulsars: A catalogue of more than 700
pulsars. Pulsars are neutron stars, former supergiants that have been compressed
into spheres with diameters of only a few tens of kilometres. Created by Ulf Teras.
Stars: A star is any body which burns or
once burned hydrogen fuel. The energy and light produced in stars comes from the fusion of hydrogen atoms. As stars grow older, they use up their supply of hydrogen and have to find other sources of energy. When they reach this point, they become either red giants or supergiants, depending on their size. As they continue to use up energy, stars eventually become either white dwarfs or, in the case of very massive stars, neutron stars or black holes.
The star database in Starry Night Pro 5.0 is actually a compilation of 3 databases: the Hipparcos catalogue, the Tycho-2 catalogue, and the USNO-A2 catalogue.
The Hipparcos and Tycho-2 catalogues come from a European Space Agency project to determine the distance to our nearest stars. The Hipparcos catalogue has about 100 000 stars and the Tycho-2 catalogue has about two million. Find out more about these catalogues on their official web page: http://a
stro.estec.esa.nl/ SA-general/Projects/Hipparcos/ hipparcos.html
Starry Night Pro 5.0 uses the USNO-A2 star database for dim stars not included in the Hipparcos or Tycho catalogues. About 16 million stars as dim as 15th magnitude can be accessed. These stars will only be visible if you chose the “Full Install” or the “Custom Install” options when you installed Starry Night Pro 5.0.
The entire USNO-A2 star database contains 500 million stars! This database is far too large to fit on a CD, so Starry
80 Starry Night Pro 5.0 User’s Guide
Night Pro 5.0 allows you to download portions of this database from the Internet. See “Adding Objects 3 (Stars)
” on
page 146 for more information.
Tip: Our Sun is an ordinary star. However, in Starry Night Pro 5.0, it is a member of the “Planets/Moons” database, not the “Stars” database.
Databases 3 (Deep Space)
This includes all objects outside of our galaxy. It also includes databases that include objects both within and outside of our galaxy. For example, the Messier catalogue includes globular clusters, which are inside our galaxy, but it also includes other galaxies, so it is classified in the “Deep Space” category.
Messier Objects: This category includes
the 110 Messier objects, originally catalogued by French astronomer Charles Messier and colleagues in the late 1700’s. Messier was trying to identify all “fuzzy” deep space objects that might be mistaken for comets. The Messier objects are a mixture of star clusters, nebulae, and galaxies (plus a few objects that don’t fit into any of these categories). Many of the Messier objects are favourite targets for amateur astronomers. For each object in the Messier catalogue, Starry Night Pro
5.0 includes a detailed image and a text description with observing tips.
Bright NGC Objects:
This database is a grab bag of famous deep space objects (mostly star clusters, galaxies, and nebulae) that were excluded from the Messier catalogue for one reason
or another. Many of the objects were missed by Messier because they are more easily seen from the Southern Hemisphere, and could only be seen low on the horizon (if at all) from Messier’s base in Paris. For each object in this catalogue, Starry Night Pro 5.0 includes a detailed image and a text description with observing tips.
NGC-IC: The NGC/IC (New General
catalogue/Index catalogue) is a more extensive listing of star clusters, galaxies and nebulae, It was originally compiled by J.C. Dreyer from 1888-1908 and includes about 13 000 objects. Starry Night Pro 5.0 uses an updated version of this database, compiled by Wolfgang Steinecke and converted into Starry Night format by Peter Enzerink, which fixes many errors in the original catalogue. Find out more about the NGC-IC catalogue on the web at
www.ngcic.com
Galaxies: The PGC (Principal Galaxy
.
catalogue). This database contains 980 000 galaxies brighter than magnitude 18, far more than the NGC-IC database.
Quasars: More than 18 000 quasars, BL
Lac objects, and active galaxies. All three classes of objects are the extremely luminous nuclei of very distant galaxies. There is probably a supermassive black hole at the center of each of these objects. This database was created by Ulf Teras.
Tully 3-D Database: A collection of nearly
28 000 galaxies. The neat thing about this database is that it contains 3-dimensional positions of these galaxies. You can use Starry Night Pro 5.0’s controls to view the 3-dimensional arrangement of these galaxies.Choose Favourites->Deep Space from the main menu to view some sample
Object Databases 81
files that use this database to render some 3-dimensional extragalactic views of our universe.
Hubble/Chandra/Spitzer Images: These
databases contain about 100 images taken by space telescopes. A full description for each image is provided in the Night Sky Tours section of SkyGuide. See“SkyGuide
” on page 66 to learn more
about exploring SkyGuide.
User Images: This is a database of images
which you have added to Starry Night Pro
5.0 yourself. Initially, this database will be blank. See “User Images
” on page 148 to
learn how to add your own images.
Databases 4 (Other)
Certain databases are not included in any of the above layers, and are listed separately in the Other category of the Options pane. Most databases fall into this category because they overlap with one or more of the databases described in the first 4 layers. For example, the Other category includes a database of planetary nebulae. However, many of these nebulae are already included in the “Messier Objects”, or the “Bright NGC Objects” databases, so Starry Night Pro 5.0 would show duplicate markings for these objects, if the “planetary nebulae” database was also turned on. By default, all of the databases in the Other category are turned off, but you can turn one or more of these databases on if it suits your purpose.
Tip: Most of the databases in this category were created by Starry Night Pro 5.0 users. See “Adding Objects 4 (Databases)
” on
page 147 for information on building your own databases.
Note: The list of databases in your version of Starry Night Pro 5.0 may not be exactly the same as the following list, as we are continually adding new databases and updating existing ones. If you like to include a database you see described here, but it is not installed in your version of Starry Night Pro 5.0, please visit the
Knowledge Base
area of our web site and
do a search for “databases”.
Abell Cluster of Galaxies: The catalog was
originally prepared at the Bulgarian Academy of Sciences. The Abell clusters are rich, compact clusters of galaxies identified by Abell (1958). These clusters were identified on the red plates of the Palomar Observatory Sky Survey (POSS). The magnitude, if known, refers to the brightest member. There are 2712 clusters in this catalog.
Arp Peculiar Galaxies: A catalog of 338
peculiar galaxies gathered by Dr. Halton C. Arp in his Atlas of Peculiar Galaxies. The catalog is a selection of unusual or peculiar galaxies, interacting pairs or larger groups. Arp compiled the list with photographs from the Palomar 200-inch telescope in 1966. Magnitude, if known, refers to brightest member.
Caldwell: The Caldwell catalogue consists
of 109 deep space objects not in the Messier catalogue that can be viewed with a small telescope. This catalogue was originally compiled by Sir Patrick Moore, and converted to Starry Night format by Charles Gagne.
82 Starry Night Pro 5.0 User’s Guide
Celestron AAM Alignment Stars: The 28
alignment stars for Celestron's Advanced Astro-Master, a digital setting circle device. Created by Greg Miller.
Dark Nebula: 37 Dark Nebula taken from
the 2004 Observer's Handbook. Database formatted into Starry Night format by Terry Adrian.
Double Stars: The Saguaro Astronomical
catalogue of over 11 000 double stars, including almost all double stars with a primary brighter than magnitude 9 and a secondary brighter than magnitude 13, created by Steve Coe and A.J. Crayon, converted into Starry Night format by Bill Arnett.
Finest NGC: A subset of 110 of the best
deep space objects in the NGC catalogue, none of which are in the Messier catalogue. This list was originally compiled by Alan Dyer and converted to Starry Night format by Richard Weatherston.
Herschel 400: A subset of 18th century
astronomer William Herschel's catalogue of deep space objects. It is designed as a list of objects for amateurs to observe after they have seen all the Messier objects. The Herschel 400 was originally compiled by Brenda Branchett and converted to Starry Night format by Michael Desjarlais.
Local Group Galaxies: The 30 or so nearby
galaxies that form our "Local Group". All of these galaxies are within about five million light years of Earth. Created by Bill Arnett.
LX200 Alignment Stars: All of the bright
stars used to align Meade's LX200 telescope. Created by Bill Arnett.
Meteor Showers (RASC): An alternate
meteor shower database with radiant data from the Royal Astronomical Society Observer's Handbook. Created by Stephen Hutson.
Navigational Stars: The 57 bright stars
used for celestial navigation in the Nautical Almanac.
Nexstar 5 Stars: All 10 000 stars in the
star catalogue built into Celestron's Nexstar 5 and Nexstar 8 telescopes. Created by Alan Touchberry.
Nexstar Alignment Stars: The 40 bright
alignment stars for Celestron's Nexstar 5 and Nexstar 8 telescopes. Created by Brandon Beretta.
Planetary Nebulae: All planetary nebulae
from the Perek-Kohoutek catalogue. Converted to Starry Night format by Bill Arnett.
SAA 100: The top 100 non-Messier deep
space objects, as voted on by the amateur astronomy newsgroup "sci.astro.amateur". Converted to Starry Night format by Peter Enzerink.
Sky Commander Alignment Stars: The
alignment stars for the Sky Commander telescope guiding device. Created by Allan Keller.
SS2K Alignment Stars: The alignment
stars for the Vixen SkySensor 2000 telescope. Created by Bob Hillier.
Supernova Remnants: All known
supernova remnants in the Milky Way. This catalogue was created by Dr. David Green and converted into Starry Night format by Dr. Leigh Palmer. Visit Dr. Green's website:
Object Databases 83
http://www.mrao.cam.ac.uk/surveys/snrs/
to learn more about this catalogue.
UGC: The Uppsala General catalogue of
13 000 galaxies, converted into Starry Night format by Bill Arnett.
Variable Stars (AAVSO): A database of
almost 6000 variable stars built from the AAVSO (American Association of Variable Star Observers) and GCVS (General Catalogue of Variable Stars) databases, compiled by Mike Fikes.
Variable Stars (GCVS): All 31 000 stars in
the GCVS (General catalogue of Variable Stars). Based on data from Kopolev et. al (1988) and NASA/ADC (1997). Converted to Starry Night format by Marion Schmitz.
Variable Stars (GCVS-Hipparcos): Over
8300 variable stars with information from the GCVS (General catalogue of Variable Stars) Vols. 4 and 5, and the Hipparcos catalogues of Periodic and Unsolved Variables, compiled by Ray Colley.
The databases of comets, asteroids and satellites change more frequently than other databases, so Starry Night Pro 5.0 has a special method of updating these databases. Choose LiveSky->Update Comets/Asteroids/Satellites and updated satellite, comet and asteroid data files will be downloaded from our website. We update these files several times a week, so you can expect that any new comets, asteroids or satellites will be added as soon as possible. After you have downloaded the new files, you will need to exit and restart Starry Night Pro 5.0 before it will read in the new data files.
You can set up Starry Night Pro 5.0 to automatically update your comet, asteroid & satellite files. The various preferences are in the LiveSky->Preferences for Auto Updates menu.
Zwicky Cluster of Galaxies: Database
contains 9134 galaxy clusters compiled by Fritz Zwicky.
Database Updates
Our view of the universe will change over the next ten years. New moons will be discovered, bright new comets will streak towards the Sun, and new satellites will be launched into orbit. To ensure that Starry Night Pro 5.0’s library of data keeps up with these changes, several update mechanisms are built into the program.
Maximum number of objects read in at startup:
This field determines how much comet, asteroid, and satellite data Starry Night Pro 5.0 downloads from our website. The more objects you choose to download, the longer Starry Night Pro 5.0
84 Starry Night Pro 5.0 User’s Guide
will take to load when you start the program. You would only want to modify the default values for these fields if you have manually created larger comet, satellite, or asteroid databases. See “Adding Objects 2 (Multiple Solar System
Objects)” on page 146 for information on
building these databases.
Clicking this
button will download the latest comet, satellite, and asteroid data files from the Starry Night website.
Automatically check for updates from StarryNight.com every xx days:
Checking this option ensures that Starry Night will automatically connect to our website on a regular basis to update the comet, asteroid & satellite files. The updates will be performed when Starry Night Pro 5.0 is opened. You can control how often Starry Night will attempt to download the files from our website. It is recommended that you update the files at least once every two weeks. This is particulary important for satellites. The position of satellites in Starry Night Pro 5.0 will become unreliable if your data is more than a few weeks old, due to the effects of atmospheric drag.
for information on downloading star data from the Internet.
Note: It is also possible to manually modify the comet, asteroid & satellite databases. See “Adding Objects 2
(Multiple Solar System Objects)” on
page 146 for more information.
For objects other than comets, asteroids & satellites, the data does not change as frequently. However, there will still be changes to existing databases, and occasionally, new databases. You can check to see if any new data is available by choosing LiveSky->Check For Program Updates from the menu. This connects you to the updates page on our website. If any new databases are available, they will be posted on this page, along with instructions for adding them to your copy of Starry Night Pro 5.0.
Now that you know all of the different databases in Starry Night Pro 5.0, we will look at how to get more information on any of the objects in these databases.
Ask Before Connecting to the Internet: If
you check this box, Starry Night will always ask you before attempting to connect and download files, otherwise the connection will be made automatically.
Clear Star Cache: Empties the stars
downloaded from the Internet that were cached on your local hard disk. See “Adding Objects 3 (Stars)
” on page 146
Object Databases 85
Find Pane Info
In “Finding Objects
” on page 23, you learned that typing in a search for an object produced a list of items found. For each item in this list, the Find pane displays several pieces of information:
This opens the object’s
. See “Object Contextual Menu
menu
contextual
on page 86 for information on the fields in this menu.
Select/Deselect: Checking the box to the
left of the object’s name in the Find pane selects the object and labels it onscreen. See “Labeling Select Objects
” on page 37
for more information on selecting objects.
Adding Log Entries
” on page 135 for
more information about adding log entries.
Altitude: The object’s height above the
horizon. If the object has a negative altitude, it is currently beneath the horizon. If it has a positive altitude that is close to 0°, the object is just above the horizon. An altitude close to 90° means that the object is high above the horizon.
Kind: The type of object (e.g. comet,
satellite, etc.)
Database: The database that the object
comes from.
Objects in our solar system also have the following options:
Orbit: Checking this box (to the right of
the object name) draws the orbital line of the object. See “Orbits
” on page 108 for
more information on solar system orbits.
Semi-major axis: This is the distance
between an object and its parent body, at the point when the object is farthest away from the parent body. For a circular orbit, the semi-major axis is equal to the orbital radius.
Text Description: A text description of
the object. All well-known objects will have unique text descriptions, with historical information, observing tips, and other cool facts about the object. For non­descript objects such as dim stars, the description will be a generic description for the object type (i.e. red giant star).
This symbol indicates that you have created a log entry for the object.
Click to view the log entry. See
86 Starry Night Pro 5.0 User’s Guide
Object Contextual Menu
An object’s contextual menu provides a list of actions in Starry Night Pro 5.0 that can be performed on an object. You open an object’s contextual menu by clicking the right mouse button (Ctrl-clicking on the Macintosh) while the cursor is pointing at the object.
All of the items in the menu relate to the object that you clicked on. If you were not pointing the cursor at a specific object, the menu gives you options for the appearance of the sky as a whole and the constellation which you are pointing at.
See “Sky Contextual Menu
” on page 31
for information on that menu.
Tip: You can also open an object’s contextual menu from the Find pane. Type in a search for the object you are interested in, then click the arrow to the left of the object’s name in the list of found items.
The various options in the contextual menu are described below. Most of these features are discussed in more detail in other sections of the book, so only a brief description of each feature is given in this section. Don’t be overwhelmed! The options are just listed here so that you have a quick reference for all the contextual menu options in one place.
Select/Deselect: This selects or deselects
the object. If an object is selected, its name and an arrow pointing to the object will appear onscreen. See “Labeling Select Objects
” on page 37 for
more information on selecting objects.
Centre: This adjusts your view so that the
object is at the centre of the screen and remains locked in the centre of the screen as time passes. This is handy if you want to watch a planet’s motion against the background stars, for example.
Note: If you are centred on an object and it falls beneath your horizon, your view of it will be obscured by the horizon.
Magnify: This zooms in on the object so
that you get a close-up view. Objects within our solar system and deep space objects in the Messier and Bright NGC Objects databases all have detailed images. Stars other than our Sun are just shown as points of light, and many of the objects from other databases will just have position markers instead of images.
Go There: This changes your location to
the surface of the object in question (if the object is a star, you will be placed nearby). First your viewing direction will change, then you will begin to lift off your current body and fly in the direction of the celestial body you have chosen. Your distance from the Sun will appear along the bottom of the screen as you fly to the new location. The Heads-Up Display (HUD) will identify any objects that you pass by during your journey. The “Go There” option is only available for objects with accurate 3-dimensional position information. There are many other ways to change your location in
Object Databases 87
Starry Night Pro 5.0. See “Changing Your Viewing Location
” on page 102 for more information. However, the contextual menu is the
only way to
change your location so that you are viewing from another star or galaxy.
Tip: If you zoom in for a close-up of a planet and then right-click the mouse (Ctrl-click on the Mac) and choose Go There, your location on the new planet will be the position on the surface where you clicked the mouse. This can be helpful if you want to watch eclipses on other planets. You can zoom in on Jupiter (for example) until you can see the shadow caused by one of its moons passing in front of the Sun. Right-clicking on the shadow and choosing Go There will allow you to watch a solar eclipse from Jupiter!
Start\Stop Graphing: This plots the
object’s motion with Starry Night Pro 5.0’s graphing feature. See “Graph
” on
page 119 for more information.
Generate Ephemerides: This allows you to
create a list of printable ephemeris tables for any object in Starry Night Pro 5.0. See “Ephemeris Generator
” on page 121 for
more information.
Add/Edit Image: This allows you to add
an image of this object to Starry Night Pro
5.0, or edit the image, if the object already has an image. See “User Images page 148 and “Modifying Images
” on
” on
page 152 for more information.
Add To Planner: This adds the object to
your observation planner list. See “Observation Planner
” on page 116 for more information on using the observation planner.
Add FOV Indicator: This adds a new field
of view (FOV) indicator, centred on the object. See “Adding other indicators
” on
page 57 for more information.
Add Log Entry/Log Entries: Creates a log
entry for you to add observing notes about an object. See “Adding Log Entries
” on page 135 for more information on log entries.
Note: If you have already added a log entry for an object, the object’s contextual menu will list these entries.
Show Info: This opens the Info pane,
which displays much more information on the object. All the fields in the Info pane are explained in “Info Pane
Online Info: This will bring up a page on
” on page 88.
LiveSky which has a listing of web resources with more information about the object.
Objects in our solar system have a few additional entries in their contextual menu.
Graph Elongation of Moons: Only an
option for planets with moons, this plots the elongation of the planet’s moon(s) using the graphing feature. See “Graph
on page 119 for more information.
Orbit: Draws the orbital line of the object.
See “Orbits
” on page 108 for more
information on solar system orbits.
Local/Celestial Path: Turns on the local or
celestial path of the object, which shows how the object moves over time. See “Local and Celestial Paths
” on page 100
for more information.
88 Starry Night Pro 5.0 User’s Guide
New Asteroid/New Comet/New Satellite/ Add Moon Orbiting...
All of these options allow you to add a new object using the Orbit Editor. The type of object that you can add depends on the type of object that you open a contextual menu for. For example, if you open a planet’s contextual menu, the “Add Moon Orbiting...” option appears. See “Adding Objects 1
(Individual Solar System Objects)” on
page 139 for more information on adding objects with the Orbit Editor.
Edit Surface Image: An option only for
solar system bodies with surface images, this allows you to modify the surface image or replace the image entirely. See “Modifying Images
” on page 152 for more
information.
Save As QuickTime VR: An option for solar
system objects. Allows you to create a 360 degree exposure of a solar system object. Unlike exporting a 2D image, the QTVR file is an interactive virtual reality scene.
Edit Orbital Elements: An option only for
objects that you have added with the Orbit Editor, this allows you to edit the object’s orbital elements. See “Adding Objects 1
(Individual Solar System Objects)” on
page 139 for more information on orbital elements and the Orbit Editor.
Delete: An option only for objects that you
have added with the Orbit Editor, this allows you to delete the object entirely from Starry Night Pro 5.0’s database.
Enlarge Moon Size: By default, the Moon’s
size is enlarged when you are viewing at a large field of view, so that you are able to easily see the Moon’s phase (the Moon is drawn at its correct size when you are zoomed in for a close-up view). By
unchecking this option in the Moon’s contextual menu, the Moon will always be drawn at its correct size, but it will be too small to see phase information when you are viewing at a large field of view.
Halo Effects: The Sun’s halo is an
atmospheric effect that occurs when the Sun’s light is scattered by our atmosphere. You can turn the sun halo on all the time, off all the time, or on in daylight only. You can also simulate lens flare. If you’re viewing a total eclipse of the Sun, you will probably wish to leave the Sun’s halo on, as this halo also serves as the Sun’s corona.
Tip: To remove the Lens Flare from the Sun, open the Sun’s contextual menu, select Halo Effects and uncheck Lens Flare.
Info Pane
You were introduced briefly to the Info pane in “Learning More About Objects
” on page 27. Recall that you can double­click on any object onscreen to automatically open the object’s Info pane. You can also open an object’s Info pane by typing in a search for the object in the Find pane, then opening the object’s contextual menu from the list of items found. Choose Show Info from the contextual menu to open the Info pane. The Info pane provides a great deal of information about any object, as well as links to several Internet features which can help you learn even more.
Note: The Info pane for an object differs in function from the object’s contextual menu.
Object Databases 89
The Info pane provides information, while the contextual menu lists possible actions.
Some of the fields in the Info pane are common for all objects, while some fields are specific to certain object types.
•General Info
This button searches our
LiveSky Internet site for more information about the object. See “LiveSky.com Object Database
” on
page 94 for more information.
Name: The name of the selected object.
Catalogue number: The object’s number in
the appropriate astronomical catalogue (if applicable).
Object Type: The object’s celestial type
(star, galaxy, planet, etc.).
Bayer: For stars only, this field gives the
star’s Bayer catalogue letter, if any. The Bayer letter is from the Greek alphabet. The brightest star in a given constellation is usually named Alpha (the first letter in
the Greek alphabet), the second brightest is named Beta, and so on. Only relatively bright stars have Bayer letters.
Flamsteed/Other: For stars only, this gives
the star’s Flamsteed number, if any. The Flamsteed system orders stars not by brightness, but by their position relative to the western boundary of the constellation they are in. The star closest to the western edge is labelled 1. Only relatively bright stars have Flamsteed numbers.
HIP Number/TYC Number: The
HIPPARCOS and Tycho project was a study done by the European Space Agency to determine the distances to nearby stars. The Tycho-2 catalogue included about two million stars and the HIPPARCOS catalogue about 100 000. For stars only, these fields give the catalogue numbers of the star in question. Not every star has a HIPPARCOS catalogue number.
More Options: Clicking this button will
bring up the objects contextual menu of options.
Logs: Lists all log entries (if any) that you
have created for this object. See “Adding
Log Entries” on page 135 for more
information on log entries.
Extended Info: Takes you to LiveSky and
provides a list of web resources containing more information about this object.
Export: Creates a text file with all the
information generated in the Info pane.
Rise/Transit/Set: The time at which the
object rises above the horizon, transits, and sets below the horizon, as viewed on the date and from the location of the active Starry Night Pro 5.0 window. An object’s transit time is the time at which it is
90 Starry Night Pro 5.0 User’s Guide
highest in the sky. At its transit time, an object will be due south in the sky (if you are viewing from the Northern Hemisphere), or due north (if you are viewing from the Southern Hemisphere).
Tip: Clicking on the rise/set/transit buttons will change the time in Starry Night Pro 5.0 to reflect the rise/set/transit times for the object.
• Description
A text description of the object. All well­known objects will have unique text descriptions, with historical information, observing tips, and other cool facts about the object. For non-descript objects such as dim stars, the description will be a generic description for the object type (i.e. red giant star).
• Position in Sky
This section lists the constellation that the object is currently in, and the object’s positional co-ordinates in many different co-ordinate systems. The meanings of each of these co-ordinates are described in “Guides 1 (Co-ordinate Systems)
” on
page 50.
• Position in Space
Tip:
You can also open the text description for any object by clicking the icon
that appears to the right of an object’s name in the list of items found in the Find pane.
This section has information on the object’s 3-D position in space, if known.
Distance from observer: The object’s
distance from your current location.
Note: the distances to stars are only given for those stars in the HIPPARCOS catalogue. The distances to stars are known only approximately and should be treated with some caution. The closer a
Object Databases 91
star is, the more accurate its distance measurement is likely to be. The distances to stars within a few hundred light years are relatively accurate, but distances are much less accurate for stars farther away than this.
Distance from Sun: The object’s distance
from the Sun.
Proper Motion RA/Dec: Stars are not fixed
in space, and most are in fact moving quite rapidly. Because of their great distance from us, however, their positions appear constant. Only on a timescale of hundreds or even thousands of years can we actually see the shifting positions. These fields (for stars only) describe how much the star’s equatorial co-ordinates are shifting each year due to the star’s motion.
•Other Data
The fields that appear in this category depend greatly on the database that the object is from. Different databases will have different information fields.
Star Information Fields: For stars, the
following fields are present:
Variability: This indicates whether a star’s
apparent magnitude (and, therefore, its brightness) varies with time, and by how much.
Radius: This measures the star’s radius, in
terms of the Sun’s radius. Red giant stars can be hundreds of times larger than the Sun.
Double/Multiple: This field indicates
whether a star is part of a multiple star system. About half of the stars in the sky are part of a multiple star system.
Magnitude: This shows a star’s apparent magnitude
, a value which measures its brightness in the sky. The idea for assigning magnitudes originated with Greek astronomer Hipparchus (190-120 BC). He catalogued all the visible stars he could see and assigned them magnitudes from 1 to 6, the brightest stars having a value of 1.
Contemporary astronomers have refined Hipparchus’ system, so that the system now includes larger numbers for dimmer stars, and negative numbers for very bright objects. The faintest stars that can be seen by the Hubble Space Telescope are in the 26 to 28th magnitude range — very dim stars indeed!
Note: Many newcomers to astronomy get confused by the fact that the greater an object’s magnitude, the dimmer it is. An object with magnitude -5 is much brighter than an object with magnitude 0, which in turn is much brighter than an object with magnitude 5.
The Sun has a magnitude of about -28, while the brightest star in the night sky is
92 Starry Night Pro 5.0 User’s Guide
the dog star Sirius, which has a magnitude of -1.47. The magnitudes of the planets change, depending on how close they are to Earth, but Venus, Mars and Jupiter can all have lower magnitudes than Sirius. At the other extreme, Pluto has a magnitude of about 14, far too dim to be seen with the naked eye, and even most small telescopes.
Absolute Magnitude: The magnitude we
normally use when talking about objects is the apparent magnitude, which compares how bright they are as seen from Earth. But this doesn’t tell us much about the intrinsic brightness of an object, because the bodies we see in the sky are spread out over a wide range of distances. The Sun produces the same amount of light as the average star in the sky, but it is far, far brighter than anything else simply because it is so close to us.
Absolute magnitude
tells us how bright objects would appear if they were all at the same distance (the distance we use is arbitrary, but has been chosen to be 10 parsecs). As with apparent magnitude, a lower absolute magnitude means a brighter body.
Temperature: This is the star’s surface
temperature, given in degrees Kelvin (to get a star’s temperature in Celsius, just subtract 273 from its temperature in Kelvins). The Sun has a temperature of about 5700 K.
B-V Colour: This is a way of measuring a
star’s colour. An average star has a B-V value of around 0. If a star has a negative B-V value it is on the bluish side of the spectrum. If it has a positive B-V value it is on the reddish side of the spectrum. The more negative or positive a star’s B-V, the more blue or red it will appear. A star’s
colour is directly related to its temperature: blue stars are hotter and red stars are cooler.
Luminosity: Luminosity measures the total
light and energy output of a star. It is different from apparent magnitude, because it measures not only visible light, but also the energy released as infra-red waves, X-rays, and radio waves.
Extrasolar planet information fields:
If you use the Options pane to turn on markers for stars with
extrasolar planets, the Info pane for stars with extrasolar planets will have additional information fields. This information will also appear in the Heads­Up Display (HUD) when you point the cursor at a star with an extrasolar planet.
Extrasolar mass: The mass of the
extrasolar planet, in relation to the mass of Jupiter.
Extrasolar semi-major axis: A measure of
the planet’s distance from its central star, in astronomical units (AU). 1 AU is the average distance between Earth and the Sun.
Extrasolar period: The time needed for the
planet to make 1 complete revolution around its central star.
Extrasolar eccentricity: A measure of the
shape of the extrasolar planet’s orbit. The larger a planet’s eccentricity, the more that its distance from its parent star (and also its surface temperature) will vary throughout its orbit.
Object Databases 93
Extrasolar inclination: The tilt of the
planet’s orbit, relative to our viewing position on Earth.
Note: This is a different definition of inclination than is used for objects within our solar system (e.g. comets, asteroids, satellites, moons) because the tilt is measured relative to our viewing position, not to the central body’s equator. See “Orbital Elements
” on page 140 for the definition of inclination for objects within our solar system.
Extrasolar radius: The radius of the
extrasolar planet.
Solar System Object Information Fields:
For objects within our solar system, the following information fields are present:
number of days that have passed since the Moon was last new.
Orbit Size: The radius of the orbit that the
object makes around its parent body.
Angular Size: This measures the angular
width of the object (the field of view that it occupies in the sky).
Disc Illumination: This shows how much
of a planet’s face is illuminated by sunlight (the rest is in shadow), as seen from your current position. For example, when the Moon is half full, its disc illumination is about 50%.
Planet oblateness: This measures how
much an object is “squished”, in other words, how much it deviates from a perfect sphere. A perfect sphere would have an oblateness of 0. The larger an object’s oblateness, the more “squished” it is.
Mass: The object’s mass (if known).
Radius: The object’s radius (if known).
Apparent magnitude: The object’s apparent magnitude, a measure of its
brightness in the sky. See Magnitude
” on page 91 for more information on apparent
magnitude.
Age: Only an option for the Moon, this
gives the Moon’s current phase, and the
Max. Mag. From Earth: The apparent
brightness of planets and other objects in the solar system changes as the object moves in its orbit, due to the object’s changing distance from Earth and the object’s disc illumination. This field gives the apparent magnitude of the object when it is at its brightest.
Length of Sidereal/Solar Day: An object’s sidereal day is the time that it takes to
rotate once, relative to the fixed stars. An object’s
solar day is the time that it takes to
rotate once, relative to the Sun. This is also the average time between sunrises on the planet’s surface. These two time periods differ by a large amount only when the length of a planet’s sidereal day is a significant fraction of the length of the
94 Starry Night Pro 5.0 User’s Guide
planet’s year. On Earth, the time periods are almost identical, with the 24 hour solar day being only four mintes longer than the sidereal day.
Length of Year: For objects that orbit the
Sun, a year is the amount of time that it takes for the object to complete one full orbit.
Other Object Information Fields:
The information fields for objects other than stars and solar system objects will vary. Often the only pieces of information are the object’s magnitude and angular size.
LiveSky.com Object Database
In “LiveSky Pane
” on page 71, you
learned how to use Starry Night Pro 5.0’s LiveSky pane to access live, up-to-the­minute images of celestial phenomena. You can also use LiveSky to locate information on the Internet for any object.
LiveSky.com button in the object’s Info pane. This will bring up a page on LiveSky which has a listing of web resources with more information about the object. It will also give you the option of searching other sites on the Internet, both general-purpose search engines and astronomy-specific pages, for information on your object.
Example: Finding Web Pages for the Moon
1Open the “moon”, then double-click on the Moon’s name to centre on the Moon.
2Open the
3Click the
Find pane and type in
Info pane.
LiveSky.com button from the
Info pane. At this point your web browser
should go to our LiveSky database and open a page with several links to websites with more information about the Moon. Click on any of these links to read interesting facts and trivia about the Moon, and to see lots of pictures and figures.
Some of the links in our LiveSky database will appear for all objects (these may be changed if better sources become available). These links are described below.
You can access the LiveSky database for any
object in Starry Night by clicking the
Digitized Sky Survey: The Digitized Sky
Survey (DSS) is a collection of images obtained with two Schmidt telescopes and converted into digital format by the Space Telescope Science Institute. The digitized data allows the user to generate an image of any area in the sky. Clicking this link on our webpage will automatically generate a DSS image of the object you originally clicked on in Starry Night Pro 5.0. See “Downloading Photographic Images
” on page 75 for more information on the Digitized Sky Survey.
HEASARC Astrobrowse: Clicking this link
will search dozens of astronomy databases for information on your object. A new window will open with each database being searched listed on the left side. When the search for that database has been completed, a green “happy-face” icon will appear beside the name of the database. You can then click the name of the database to retrieve the information.
Tip: It is also possible to visit the “front page” of LiveSky by opening a web browser and directing it to
www.livesk
y.com . This page has listings
and brief descriptions of astronomy-related websites, sorted into different categories, much like the site Yahoo!, but devoted exclusively to astronomy.
Object Databases 95
96 Starry Night Pro 5.0 User’s Guide
Chapter 6
Bending Space & Time
This chapter will show you how to take full advantage of Starry Night Pro 5.0’s planetarium capabilities. You will learn how to start, stop, speed up and slow down the flow of time, and change your location to view from anywhere on or off the surface of Earth - you’ll even fly a spaceship! Several examples will help you master the control of time & space.
98 Starry Night Pro 5.0 User’s Guide
Time Flow
By default, time in Starry Night Pro 5.0 advances at the same rate as real time. If you run Starry Night Pro 5.0 for one hour, the time onscreen will also advance by one hour. As the time in Starry Night Pro 5.0 changes, the screen continuously updates to reflect the changing sky.
Note: This means that the
rate of time flow
is the same as real time, but the time itself may not be the same. For example, let’s say you open Starry Night Pro 5.0 at 8 p.m. You then change the time onscreen to 1 p.m. and run the program for one hour. At the end of the hour, the actual time will be 9 p.m, but the time that Starry Night Pro 5.0 shows will be 2 p.m.
Changing Time Flow Rate: One of the nice
things about Starry Night Pro 5.0 is that you can change the rate at which time flows. Just like nature programs use time­lapse photography to show processes which take place too slow to see in real time, you can speed up or slow down time to get the best possible views of an astronomical event.
The rate of time flow is shown immediately to the right of the date and time in the toolbar.
Clicking the arrow opens a pull-down menu that displays a list of possible time steps. The steps fall into two categories: multiples of real time, and
discrete time steps.
Time steps that are multiples of real time
(i.e. 30x) simply advance the time in Starry Night Pro 5.0 at a rate equal to a multiple of the real rate of time flow. For example, a time step of 30x would cause the time in Starry Night Pro to advance at 30 times the real rate of time flow. Obviously, the larger the multiple, the faster time would advance onscreen. Discrete time steps update the time by a specific increment. For example, a time step of 3 minutes means that every time the screen updates, the time in Starry Night Pro 5.0 is advanced by 3 minutes. Discrete time steps are often useful when simulating astronomical events. For example, assume you wanted to see how Jupiter’s position in the sky changes over the next few months. You could set the time to sometime in the evening (for example, 9 p.m.) and then set the time step to 1 day. Starry Night Pro 5.0 would run time forward, showing the sky at 9 p.m. each night. If you had chosen a multiple of real time instead of a discrete time step, you would see an alternating cycle of day and night, instead of seeing the sky at the same time each night.
A few of the discrete time steps listed in the pull-down menu may be unfamiliar to you:
Sidereal day: This is the time it takes for
the Earth to rotate once on its axis. It is four minutes shorter than the day we are familiar with, which is called the solar day. The days are not exactly the same length due to the revolution of Earth around the Sun.
Sidereal month: This is the time it takes
for the Moon to rotate once around Earth, approximately 27.3 days. This is shorter
than the month we are familiar with (the lunar month), again due to the revolution of Earth around the Sun.
Lunar month: This is the time interval
between two full moons, as seen on Earth. It is about 29 1/2 days.
Customizing Time Steps:
You are not limited to the choice of time steps that appear in the time step pull-down menu. If
you click on the numerical part of the current time step, it will light up and you can type in a numerical value. This will let you change the time step from 1 day to 7 days, for example.
You can also create entirely new discrete time steps. To do this, choose Edit from the bottom of the time flow pull-down menu. This opens a new dialog box, which lists the existing time steps and their values. Double-click on any of the existing time steps to change their values, or click the “+” sign in the bottom left corner of this dialog box to define a new time step. For example, you could create a “Martian day”, the average time between sunrise and sunset as seen from Mars!
Bending Space & Time 99
Time Flow Modes
In the above section, you learned how to change the rate of time flow, but not the mode of time flow. Time simply flowed forward continuously, advancing every time the screen updated. This is known as the “Forward” mode and is one of 5 different time flow modes in Starry Night Pro 5.0. You change the time mode using the VCR-like controls in the toolbar.
Single Step Backward: Moves the
time backwards by one time step and
then freezes time.
Backward: Runs time backwards
continuously. Each time the screen is updated, the time moves backward one time step.
100 Starry Night Pro 5.0 User’s Guide
Stop: Freezes time at the current
value.
Forward (Play): Runs time forward
continuously. Each time the screen is updated, time moves forward one time step. This is the default time flow mode.
Single Step Forward: Moves the time
forward by one time step and then
freezes time.
Tip: If you want to view the sky at a precise time, first press the “Stop” button, and then type in the viewing time. If you type in the viewing time first, the time shown onscreen may update before you can press the “Stop” button.
Specifying Frame Rate: By default, when
the time mode is Forward or Backward, the screen is updated continuously. The number of updates performed per second will depend on the speed of your processor and graphics card. You can also specify the number of updates per second. To do this, choose Preferences from the File menu (Windows) or the Starry Night Pro 5.0 menu (Macintosh) and choose Responsiveness from the dropbox in the upper left corner of the Preferences dialog box.
The “Requested Frame Rate” slider and textbox allows you to set the frame rate, which is the number of times Starry Night Pro 5.0 will update per second. If you run Starry Night Pro 5.0 on more than one computer, the advantage of specifying a requested frame rate is that any simulations you create using Starry Night Pro 5.0 will run at the same speed on both computers.
Local and Celestial Paths
Objects in our solar system move over time, relative to the background stars and galaxies. Several options in Starry Night Pro 5.0 allow you to display this motion. Right-click (Ctrl-click on the Mac) on any object in the solar system to open the object’s contextual menu. You will see options named “Local Path” and “Celestial Path”. Selecting one of these options begins to plot the appropriate path for the object in question. As time advances, this path will grow. You can turn off the path by opening the object’s contextual menu and selecting the path option again.
Note: A path is the trail an object makes over a period of time. Therefore, if time is stopped in Starry Night Pro 5.0, a path cannot be displayed.
Local Path: A local path is the apparent
trail an object would make over time, as seen from your location. The local path of an object incorporates the object’s actual motion and the effects of Earth’s rotation (assuming you are located on Earth).
Celestial Path: A celestial path is the
apparent path an object makes on the celestial sphere — the trail an object leaves over time, in relation to the fixed stars. The celestial path incorporates only the object’s actual motion and ignores the effects of Earth’s rotation.
Note: There is no local or celestial path for an object that you are located on, since that object doesn’t move in relation to you.
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