Celestron CGEM DX Instruction Manual

CGEM DX CoMputErizED Mount

INSTRUCTION MANUAL

ENGLISH

Table of ConTenTs

Introduction ..................................... 1

Warning

Assembly

Setting up the Tripod

Attaching the Accessory Tray

Attaching the Azimuth Adjustment Knobs

Attaching the Equatorial Mount

Installing the Counterweight Bar

Installing the Counterweight

Attaching the Hand Control Holder

Attaching an Optical Tube to the Mount

Moving the Telescope Manually

Balancing the Mount in R.A. ....................... 5

Balancing the Mount in DEC

Adjusting the Mount

Powering the Mount

Hand Control

Alignment Procedures

Startup Procedure

Two Star Align

Quick-Align

Last Alignment

Re-Alignment

Object Catalog

Setup Procedures

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Adjusting the Mount in Altitude

Adjusting the Mount in Azimuth

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Hand Control Operation

............................... 8

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East/West (E/W) Filtering

.................................. 10

................................ 10

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Selecting an Object

Slewing to an Object

Finding Planets

Tour Mode

Constellation Tour

Direction Buttons

Rate Button

Tracking Mode

Tracking Rate

Date / Time

User Deﬁned Objects

Get RA/DEC

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. . . . . . . . . . . . . . . . . . . . . . . 9

Goto R.A/ Dec .............................. 12

Identify

Pr e cise G oTo

Scope Setup Features

Setup Time-Site

Anti-backlash

Filter Limits

Direction Buttons

Goto Approach

Autoguide Rate

OTA Orientation

Meridian

Mount Settings

RA Limits

Utility Features

Calibrate Mount

Home Position

Light Control

Factory Settings

Version

Get Axis Position

Goto Axis Position

Hibernate

Sun Menu

Scrolling Menu

Set Mount Position

Turn On/Off GPS

Turn On/Off RTC

Periodic Error Correction (PEC)

Astronomy Basics

The Celestial Coordinate System

Motion of the Stars

Polar Aligning the Mount

All-Star Polar Align

Finding the North Celestial Pole

Optional Accessories

Appendix A – Technical Speciﬁcations

Appendix B - Glossary Of Terms

Appendix C - RS-232 Connection

Appendix D – Maps Of Time Zones

Sky Maps

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InTroduCTIon

Congratulations on your purchase of the Celestron CGEM DX Series Mount! The CGEM DX series continues in Celestron’s proud tradition combining large aperture optics with the sophistication and ease of use of our computerized GoTo mount.

If you are new to astronomy, you may wish to start off by using the built-in Sky Tour feature, which commands the mount to ﬁnd the most interesting objects in the sky and automatically slews to each one. Or if you are an experienced amateur, you will appreciate the comprehensive database of over 40,000 objects, including customized lists of all the best deep-sky objects, bright double stars and variable stars. No matter your level of experience, the CGEM DX mount telescopes will unfold for you and your friends all the wonders of the Universe.

Some of the many standard features of the telescope include:

• Fullyenclosedopticalencodersforpositionlocation.

• Ergonomicallydesignedmountthatdisassemblesinto

compact and portable pieces.

• Databaselterlimitsforcreatingcustomobjectlists.

• Storageforprogrammableuserdenedobjects;

and many other high performance features!

Take time to read through this manual before embarking on your journey through the Universe. It may take a few observing sessions to become familiar with your mount, so you should keep this manual handy until you have fully mastered your telescope’s operation. The hand control has built-in instructions

to guide you through all the alignment procedures needed to have the telescope up and running in minutes. Use this manual in conjunction with the on-screen instructions provided by the hand control. The manual gives detailed information regarding each step as well as needed reference material and helpful hints guaranteed to make your observing experience as simple and pleasurable as possible.

The CGEM DX mount is designed to give you years of fun and rewarding observations. However, there are a few things to consider before using your telescope that will ensure your safety and protect your equipment.

WarninG

• Neverlookdirectlyatthesunwiththenaked eyeorwithatelescope(unlessyouhavethe propersolarlter).Permanentandirreversible

eye damage may result.

• Neveruseyourtelescopetoprojectanimageofthesunonto

any surface. Internal heat build-up can damage the telescope and any accessories attached to it.

• NeveruseaneyepiecesolarlteroraHerschelwedge.

Internal heat build-up inside the telescope can cause these devices to crack or break, allowing unﬁltered sunlight to pass through to the eye.

Never leave the telescope unsupervised, either when children are present or adults who may not be familiar with the correct operating procedures of your telescope.

D E

Mount

1. Equatorial Mount

2. Latitude Adjustment

Knob

. Tripod

4. Hand Control

Figure 2-1 – CgeM DX Mount

5. Tripod Center Leg Brace/Accessory Tray

Counterweight(s)

7. Counterweight Bar

8. Telescope Mounting

Platform

Control Panel

A. On/Off Switch

B. 12v Input Jack

C. Hand Control Port

D. AUX Port

E. Autoguider Port

assembly

The Celestron CGEM DX mount is shipped in three main boxes. In separate boxes are the following:

• EquatorialMountwithHandControl,CounterweightBar

and tripod adapter plate included

• Tripod

• Counterweight(s)

Remove all the pieces from their respective boxes and place on a ﬂat, clear work area. A large ﬂoor space is ideal. When setting up your Celestron mount you must start with the tripod and work up from there. These instructions are laid out in the order each task should be performed.

SEttinG up thE tripoD

The CGEM DX tripod comes with an all metal center leg brace / accessory tray to give rock solid support to the mount.

The tripod comes fully assembled with a metal plate, called the tripod head that holds the legs together at the top. In addition, there is a central rod that extends down from the tripod head that attaches the accessory tray between the legs. To set up the tripod:

1. Stand the tripod upright and pull the tripod legs apart until each leg is fully extended. The tripod will now stand by itself. Once the tripod is set up, you can adjust the height at which it stands.

2. Loosen the lever on the leg clamp so that the tripod leg can be adjusted.

3. Slide the center portion of the tripod leg away from the tripod head until it is at the desired height.

4. Tighten the levers on each leg clamp to hold the legs in place.

5. Once that it is fully assembled, rotate the tripod so that one of the legs is pointing roughly towards north.

To transport your tripod, remove the knob and lower the accessory tray far enough to rotate it until the three recesses line up with each leg. Collapse the legs so that each leg falls into one of the recesses. Secure the legs together with the nylon strap attached to the tripod leg.

attaChinG thE aziMuth aDjuStMEnt KnobS

To ensure safe shipment of your CGEM mount, the Azimuth Adjustment Knobs have been removed from the mount and will need to be attached.

Before securing the mount to the tripod as shown in Fig. 2-4:

1. Locate the Azimuth Adjustment Knobs from the box containing the CGEM DX mount.

2. Thread one knob into each of the holes located on either side of the mount.

3. Only thread the knobs about half way in, leaving enough space for the tripod Alignment Peg which will need to ﬁt between the screw tips.

Accessory Tray / Leg Support

Leg

Clamp Lock

Levers

Figure 2-2

attaChinG thE aCCESSory tray

1. Slide the accessory tray over the central rod so that the three cup indents are pushing against the inside of the tripod legs.

2. Thread the accessory tray knob on to the central rod and tighten.

Figure 2-3

attaChinG thE Equatorial Mount

The equatorial mount allows you to tilt the telescope’s axis of rotation so that you can track the stars as they move across the sky. The CGEM DX mount is a German equatorial mount that attaches to the tripod. On one side of the tripod head there is a metal alignment peg for aligning the mount. This side of the tripod will face north when setting up for an astronomical observing session. Before attaching the equatorial head mount to the tripod, the tripod mounting adapter must ﬁrst be attached to the tripod:

1. Place the tripod mounting adapter over the top of the tripod head.

2. Rotate the adapter so that the holes line up with holes along the side of the tripod head. Make sure the alignment peg is over the tripod leg that you want to be facing north when aligning.

3. Secure the mounting adapter to the tripod head using the three screws and washers provided.

4. Thread the center support rod up through the center of the tripod mounting adapter until the threads end.

The center support rod should now be captured by the tripod mounting adapter and is ready to accept the equatorial mount.

5. Locate the azimuth adjustment screws on the equatorial mount (Fig 2-3).

6. Retract the screws so they do not extend into the azimuth housing on the mount.

7. Hold the equatorial mount over the tripod adapter so that the azimuth housing is above the metal peg.

8. Lower the equatorial mount on the tripod so that the two are ﬂush.

9. Thread the knob (attached to the central rod) on the underside of the tripod head into the bottom of the equatorial mount to hold it ﬁrmly in place.

Equatorial Mount

Alignment Peg

Tripod Mounting Adapter

4. Thread the counterweight bar into the opening until tight.

5. Tighten the counterweight bar lock nut fully for added support.

Once the bar is securely in place you are ready to attach the counterweight.

Since the fully assembled telescope can be quite heavy, position the mount so that the polar axis is pointing towards north before the tube assembly and counterweights are attached. This will make the polar alignment procedure much easier.

inStallinG thE CountErWEiGht

Depending on which telescope model you have, you will receive either one, two or three counterweights. To install the counterweight(s):

1. Orient the mount so that the counterweight bar points toward the ground

2. Remove the counterweight safety screw on the end of the counterweight bar (i.e., opposite the end that attaches to the mount).

3. Loosen the locking screw on the side of the counterweight.

4. Slide the counterweight onto the shaft (see Figure 2-5).

5. Tighten the locking screw on the side of the weight to hold the counterweight in place.

6. Replace the counterweight safety screw.

Heavy Duty Tripod

Center Support Rod

Figure 2-4

Tripod Head

inStallinG thE CountErWEiGht bar

To properly balance the telescope, the mount comes with a counterweight bar and at least one counterweight (depending on model). To install the counterweight bar:

1. Locate the counterweight bar locking nut from the box containing the CGEM DX mount (see Fig 2-5).

2. Thread the counterweight bar through the rounded end of locking nut until the threads pass all the way through and the locking nut can go no further.

3. Locate the opening in the equatorial mount on the DEC axis.

Counterweight Bar Locking Nut

Counterweight Bar

Locking Screw

Counterweight

Safety Screw

Figure 2-5 – Mount shown with two Counterweights

(CgeM DX 1400)

attaChinG thE hanD Control holDEr

The telescope comes with a hand control holder to place the computerized hand control. The hand control holder comes attached to the tripod leg and can be easily removed for convenient use. To use the hand control plug the phone jack connector into the hand control port labeled on the electronics control panel.

Hand Control Holder

Figure 2-6

observe different objects. To make rough adjustments, loosen the R.A. and DEC clutch knobs slightly and move the telescope in the desired direction.

Both the R.A. and DEC axis have lock levers to clutch down each axis of the telescope. To loosen the clutches on the telescope, rotate the lock levers counterclockwise.

DEC Lock

RA Lock

attaChinG an optiCal tubE to thE Mount

The CGEM DX mount is equipped with a mounting plate that accepts the Celestron CGE style (3”) dovetail bar. Before you

attach the optical tube, make sure that the declination and

rightascensionclutchknobsaretight(seeFigure2-8)and thecounterweight(s)aresecurelyinstalled. This will ensure

that the mount does not move suddenly while attaching the telescope. To mount the telescope tube:

1. Loosen the mounting screw on the side of the telescope mounting platform. This allows you to slide the dovetail bar onto the mount.

2. Remove the safety screw located at the front of the dovetail bar.

3. Slide the dovetail bar on the telescope tube into the mounting platform of the mount.

4. Tighten the mounting screw on the side of the mounting platform to hold the telescope in place.

Now that the optical tube is securely in place, the visual accessories can now be attached to the telescope.

Safety Screw

Figure 2-8

balanCinG thE Mount in r.a.

To eliminate undue stress on the mount, the telescope should be properly balanced around the polar axis. Proper balancing is crucial for accurate tracking. To balance the mount:

1. Verify that the telescope is securely attached to the telescope mounting platform.

2. Loosen the R.A. lock lever and position the telescope off to one side of the mount. The counterweight bar will extend horizontally on the opposite side of the mount.

3. Release the telescope — GRADUALLY — to see which way the telescope “rolls.”

4. Loosen the set screws on the side of the counterweight so it can be moved the length of the counterweight bar.

5. Move the counterweight to a point where it balances the telescope (i.e., the telescope remains stationary when the R.A. clutch knobs are loose).

6. Tighten the screw on the counterweight to hold it in place.

While the above instructions describe a perfect balance arrangement, there should be a SLIGHT imbalance to ensure the best possible tracking. When the scope is on the west side of the mount the counterweight should be slightly imbalanced to the counterweight bar side. And when the tube is on the east side of the mount there should be a slight imbalance toward the telescope side. This is done so that the worm gear is pushing against a slight load. The amount of the

Dovetail

Bar

Telescope

Mounting

Screw

Figure 2-7

MovinG thE tElESCopE Manually

In order to properly balance your telescope, you will need to move your telescope manually at various portions of the sky to

Figure 2-9

imbalance is very slight. When taking astrophotographs, this balance process can be done for the speciﬁc area at which the telescope is pointing to further optimize tracking accuracy.

It is best to always make ﬁnal adjustments in latitude by moving the mount against gravity (i.e. using the rear latitude adjustment screw to raise the mount).

balanCinG thE Mount in DEC

Although the telescope does not track in declination, the telescope should also be balanced in this axis to prevent any sudden motions when the DEC lock lever is loose. To balance the telescope in DEC:

1. Loosen the R.A. clutch lock lever and rotate the telescope so that it is on one side of the mount (i.e., as described in the previous section on “Balancing the Mount in R.A.”).

2. Tighten the R.A. lock lever to hold the telescope in place.

3. Loosen the DEC clutch lock lever and rotate the telescope until the tube is parallel to the ground.

4. Release the tube — GRADUALLY — to see which way it rotates around the declination axis. DONOTLETGOOF

THE TELESCOPE TUBE COMPLETELY!

5. Slightly loosen the knobs that holds the telescope to the mounting platform and slide the telescope either forward or backward until it remains stationary when the DEC clutch is loose. Do NOT let go of the telescope tube while the knob on the mounting platform is loose. It may be necessary to rotate the telescope so that the counterweight bar is pointing down before loosening the mounting platform screw.

6. Tighten the knobs on the telescope mounting platform to hold the telescope in place.

Like R.A. balance, these are general balance instructions and will reduce undue stress on the mount. When taking astrophotographs, this balance process should be done for the speciﬁc area at which the telescope is pointing.

aDjuStinG thE Mount

In order for a motor drive to track accurately, the telescope’s axis of rotation must be parallel to the Earth’s axis of rotation, a process known as polar alignment. Polar alignment is achieved NOT by moving the telescope in R.A. or DEC, but by adjusting the mount vertically, which is called altitude, and horizontally, which is called azimuth. This section simply covers the correct movement of the telescope during the polar alignment process. The actual process of polar alignment, that is making the telescope’s axis of rotation parallel to the Earth’s, is described later in this manual in the section on “Polar Alignment

Adjusting the Mount in Altitude

• Toincrease(raise) the latitude of the polar axis, turn the

rear latitude adjustment knob and loosen the front screw

(if necessary)

• Todecrease(lower) the latitude of the polar axis, turn the

rear latitude adjustment knob and tighten the front screw

(if necessary)

The latitude adjustment on the mount has a range from approximately 15° to 70°.

.”

Adjusting the Mount in Azimuth

For rough adjustments in azimuth, simply pick up the telescope and tripod and move it side to side until it is roughly pointing towards north. For ﬁne adjustments in azimuth:

1. Turn the azimuth adjustment knobs located on either side of the azimuth housing (see Fig 2-10). While standing behind the telescope, the knobs are on the front of the mount.

•Turningtherightadjustmentknobclockwisemovesthemount

toward the right.

•Turningtheleftadjustmentknobclockwisemovesthemount

to the left.

Front Latitude

Rear Latitude Adjustment Knob

Figure 2-10

Both screws push off of the peg on the tripod head, which means you may have to loosen one screw while tightening the other. The screw that holds the equatorial mount to the tripod may have to be loosened slightly.

Keep in mind that adjusting the mount is done during the polar alignment process only. Once polar aligned, the mount must NOT be moved. Pointing the telescope is done by moving the mount in right ascension and declination, as described earlier in this manual.

Adjustment Screw

Azimuth Adjustment Knob

poWErinG thE Mount

The telescope mount can be powered by the supplied car battery adapter or optional 12v AC adapter. Use only adapters supplied by Celestron. Using any other adapter may damage the electronics or cause the telescope not to operate properly, and will void your manufacturer’s warranty.

1. To power the telescope with the car battery adapter (or 12v AC adapter), simply plug the round post into the 12v outlet on the electronic panel and plug the other end into your cars cigarette lighter outlet or portable power supply (see

Optional Accessories

2. Turn on the power to the telescope by ﬂipping the switch, located on the electronics panel, to the “On” position.

Hand ConTrol

All Celestron computerized telescope come with a hand control designed to give you instant access to all the functions that your telescope has to offer. With automatic slewing to over 40,000 objects, and common sense menu descriptions, even a beginner can master its variety of features in just a few

observing sessions. Below is a brief description of the individual components of the computerized hand controller:

1. LiquidCrystalDisplay(LCD)Window: Has a dual-line,

16 character display screen that is backlit for comfortable viewing of telescope information and scrolling text.

2. Align: Instructs the telescope to use a selected star or object as an alignment position.

3. Direction Keys: Allows complete control of the telescope in any direction. Use the direction keys to move the telescope to the initial alignment stars or for centering objects in the eyepiece.

4. Catalog Keys: The hand control has keys on the hand control to allow direct access to each of the catalogs in its database. The hand control contains the following catalogs in its database:

Messier

— Complete list of all Messier objects.

NGC — Complete list of all the deep-sky objects in the Revised New General Catalog.

Caldwell — A combination of the best NGC and IC objects.

Planets — All 8 planets in our Solar System plus the Moon.

Stars — A compiled list of the brightest stars from the SAO catalog.

List — For quick access, all of the best and most popular objects in the telescope’s database have been broken down into lists based on their type and/or common name:

Named Stars Common name listing of the brightest

stars in the sky.

Named Objects Alphabetical listing of over 50 of the most

popular deep sky objects.

Double Stars Numeric-alphabetical listing of the most

visually stunning double, triple and quadruple stars in the sky.

Variable Stars Select list of the brightest variable

stars with the shortest period of changing magnitude.

Asterisms A unique list of some of the most

recognizable star patterns in the sky.

CCD Objects A custom list of many interesting galaxy

pairs, trios and clusters that are well suited for CCD imaging.

IC Objects A complete list of all the Index Catalog

deep-sky objects.

Abell Objects A custom list of the Abell Catalog

deep-sky galaxies.

Constellation A complete list of all 88 constellations.

5. Info: Displays coordinates and useful information about objects selected from the telescope database.

6. Tour: Activates the tour mode, which seeks out all the best objects for the current date and time, and automatically slews the telescope to those objects.

7. Enter: Pressing Enter allows you to select any of the telescope’s functions and accept entered parameters.

8. Undo: Undo will take you out of the current menu and display the previous level of the menu path. Press Undo repeatedly to get back to a main menu or use it to erase data entered by mistake.

9. Menu: Displays the many setup and utilities functions such as tracking rates and user deﬁned objects and many others.

10. Scroll Keys: Used to scroll up and down within any of the menu lists. A double-arrow will appear on the right side of

the LCD when there are sub-menus below the displayed

menu.Usingthesekeyswillscrollthroughthose

sub-menus.

11. Rate: Instantly changes the rate of speed of the motors when the direction buttons are pressed.

12. RS-232 Jack: Allows you to interface with a computer and control the telescope remotely.

Figure 3-1

the hanD Control

Hand Control Operation

This section describes the basic hand control procedures needed to operate all Celestron computerized telescopes. These procedures are grouped into three categories: Alignment, Setup and Utilities. The alignment section deals with the initial telescope alignment as well as ﬁnding objects in the

sky;thesetupsectiondiscusseschangingparameterssuchas trackingmodeandtrackingrate;nally,thelastsectionreviews

all of the utilities functions such as calibrating your mount, polar alignment and backlash compensation.

aliGnMEnt proCEDurES

In order for the telescope to accurately point to objects in the sky, it must ﬁrst be aligned with known positions (stars) in the sky. With this information, the telescope can create a model of the sky, which it uses to locate any object with known coordinates. There are many ways to align your telescope with the sky depending on what information the user is able to provide:

TwoStarAlign uses the entered time/location information and allows the user to select which two alignment stars the telescope will automatically slew to. One Star Align uses the same time/ location information but only uses one star for alignment. Solar System Align will display a list of visible daytime objects (planets and the moon) available to align the telescope. Quick-Align will ask you to input all the same information as you would for the Auto Align procedure. However, instead of slewing to the alignment stars for centering and alignment, the telescope bypasses this step and simply models the sky based on the information given. Finally, Last Alignment restores your last saved star alignment and switch position. Last Alignment also serves as a good safeguard in case the telescope should lose power.

Startup proCEDurE

Before any of the described alignments are performed, the telescope mount needs to be positioned so that the index marks are aligned on both the right ascension and declination axes. (see Fig 3-2).

Once the index position has been set, the hand control will display the last entered date and time information stored in the hand control.

Index

Marks

allow you to select the closest city to your observing site from a list of either international or U.S. location. Custom Site allows you to enter the exact longitude and latitude of your observing site. Select City

Database

• Thehandcontrolwillallowyoutochoosefromeither

U.S. or international locations. For a listing of U.S. locations by state and then by city, press ENTER while

United States

locations, use the Up or Down scroll key to select

International

• UsetheUpandDownScrollbuttonstochooseyour

current state (or country if International locations was selected) from the alphabetical listing and press ENTER.

• UsetheUpandDownScrollbuttonstochoosethe

closest city to your location from the displayed list and press ENTER.

Time — Enter the current local time for your area. You can enter either the local time (i.e. 08:0 0), or you can enter military time (i.e. 20:0 0 ).

• SelectPMorAM.Ifmilitarytimewasentered,thehand

control will bypass this step.

• ChoosebetweenStandardtimeorDaylightSavings

time. Use the Up and Down scroll buttons (10) to toggle between options.

• Selectthetimezonethatyouareobservingfrom.

Again, use the Up and Down buttons (10) to scroll through the choices. Refer to Time Zone map in Appendix for more information.

Date — Enter the month, day and year of your observing session.

and press ENTER.

is displayed. For international

and press ENTER.

Figure 3-2 - DeClination inDeX Marks

anD right asCension (ra) inDeX Marks

1. Press ENTER to begin the alignment process.

2. The hand control will ask the user to set the mount to its index position. Move the telescope mount, either manually or with the hand control, so that the index marked in both R.A. and Dec are aligned (see Fig 3-2). Press Enter to continue.

• Thehandcontrolwillthendisplaythelastenteredlocal

time, time zone and date.

• UsetheUp/Downkeys(10)toviewthecurrent

parameters.

• PressENTERtoacceptthecurrentparameters.

• PressUNDOtoentercurrentdate,timeandlocation

information into the hand control. The following information will be displayed:

Location — The hand control will display a list of cities to choose from. Choose the city from the database that is closest to your current observing site. The city you choose will be remembered in the hand controls memory so that it will be automatically displayed the next time an alignment is done. Alternatively, if you know the exact longitude and latitude of your observing site, it can be entered directly into the hand control and remembered for future use as well. To choose a location city:

• UsetheUpandDownscrollkeystochoosebetween

City Database and Custom Site. City Database will

Updating Your Location — Since you may not need to update your observing location as often as the date and time, it is not displayed each time you update the date and time. To update your city, press UNDO at any time when updating your date and time. Continue to press UNDO to change the state, country or to add longitude/ latitude coordinates.

Select one of the alignment methods as described below.

Note: If incorrect information is entered into the hand control, the UNDO button acts like a back space button allowing the user to re-enter the correct data.

tWo Star aliGn

Two-Star Align allows the user to select two stars on which to align the telescope. To align your telescope using the Two-Star Align method:

1. Select Two-Star Align from the alignment choices given. Based on the date and time information entered, the hand control will automatically select and display a bright star that is above the horizon.

• PressENTERtoselectthisstarasyourrst

alignment star.

• Ifforsomereasonthechosenstarisnotvisible(perhaps

behind a tree or building) press UNDO to have the hand control automatically select the next brightest star.

• OryoucanusetheUp/Downkeystobrowsetheentire

Named Star list and select any one of over two hundred alignment stars.

2. Once the telescope is ﬁnished slewing to your ﬁrst alignment star, the display will ask you to use the arrow buttons to align the selected star with the cross hairs in the center of the ﬁnderscope. When centered in the ﬁnder, press ENTER.

3. The display will then instruct you to center the star in the ﬁeld of view of the eyepiece. When the star is centered, press ALIGN to accept this star as your ﬁrst alignment star.

4. After the ﬁrst alignment star has been entered the hand control will automatically select a second alignment star and have you repeat this procedure for that star.

When the telescope has been aligned on both

East/West(E/W)Filtering

stars the display will ask you if you wish to add additional calibration stars. Calibration stars are used to improve the pointing accuracy of your telescope by compensating for subtle opto-mechanical misalignments between the telescope optics and the mount. Therefore it is usually a good idea to add at least one additional calibration star to improve the telescope’s all-sky pointing accuracy.

5. Press ENTER to select a calibration star. Select a star the same way you did with the ﬁrst two alignments stars and pres ENTER. You will notice that all the calibration stars displayed are located on the opposite side of the

In order to ensure the best possible full sky pointing accuracy, your computerized telescope automatically ﬁlters and chooses its initial alignment stars so that the ﬁrst two alignment stars are located on one side of the Meridian and any calibration stars are on the opposite side of the Meridian, as indicated by the “W” or “E” displayed in the upper-right corner of the LCD. East/West ﬁltering can be changed simply by pressing the MENU button at any time during the alignment process.

side of the sky (Meridian) as the original alignment stars. This is essential for an accurate calibration of the mount.

Finally you can chose to continue to add additional calibration stars or Press UNDO to complete the alignment.

Tips for adding calibration stars:

• Althoughforcasualobservingitisnotnecessarytoadd

calibration stars, it is recommended that you add as many as three calibration stars for optimal point accuracy.

• Calibrationstarsthatareneartheequatorofferthebest

results than stars near the poles.

• Althoughitisnotnecessarytousecalibrationstarsifthe

telescope mount has not been moved since its original alignment/calibration, it may be necessary to recalibrate the telescope if the optical tube has been removed for any reason.

onE Star aliGn

One-Star Alignment works much the same way as Two-Star Align but uses only a single star in the sky for alignment. This method of alignment is not as accurate as the two-star alignment and is recommended only for telescopes that are permanently and accurately polar aligned.

Solar SyStEM aliGn

Solar System Align is designed to provide excellent tracking and GoTo performance by using solar system objects (Sun, Moon and planets) to align the telescope with the sky. Solar System Align is a great way to align your telescope for daytime viewing as well as a quick way to align the telescope for nighttime observing.

Never look directly at the sun with the naked eye or with a telescope (unless you have the proper solar ﬁlter). Permanent and irreversible eye damage may result.

1. Select Solar System Align from the alignment options.

2. The SELECT OBJECT message will appear in the top row of the display. Use the Up and Down scroll keys (10) to select the daytime object (planet, moon or sun) you wish to align. Press ENTER.

3. Use the direction arrow buttons to carefully center the object in the ﬁnderscope. Press ENTER when centered.

4. Then, center the object in the eyepiece and press ALIGN.

Once in position, the telescope will model the sky based on this information and display Alignment Successful

Figure 3-3

the MeriDian is an iMaginary line in the sky that starts

at the north Celestial Pole anD enDs at the south Celestial

Pole anD Passes through the zenith. iF you are FaCing south,

the MeriDian starts FroM your southern horizon anD Passes DireCtly overheaD to the north Celestial Pole.

Tips for Using Solar System Align

• Forsafetypurposes,theSunwillnotbedisplayedinanyof

the hand control’s customer object lists unless it is enabled from the Utilities Menu. To allow the Sun to be displayed on the hand control, do the following:

1. Press the UNDO button until the display reads “CGEM Ready”

2. Press the MENU button and use the Up and Down keys to select the Utilities menu. Press ENTER.

3. Use the UP and Down keys to select Sun Menu and press ENTER.

4. Press ENTER again to allow the Sun to appear on the hand control display.

The Sun can be removed from the display by using the same procedure as above.

• Toimprovethetelescopepointingaccuracy,youcanusethe

Re-Align feature as described below.

quiCK-aliGn

Quick-Align uses all the date and time information entered at startup to align the telescope. However, instead of slewing to the alignment stars for centering and alignment, the telescope bypasses this step and simply models the sky based on the information given. This will allow you to roughly slew to the coordinates of bright objects like the moon and planets and gives the telescope the information needed to track objects in any part of the sky (depending on accuracy of polar alignment). Quick-Align is not meant to be used to accurately locate small or faint deep-sky objects or to track objects accurately for photography.

To use Quick-Align, simply select Quick Align from the alignment options and press ENTER. The telescope will automatically use the entered date/time parameters to align itself with the sky and display Alignment Successful

NOTE: Once a Quick-Align has been done, you can use the Re-alignment feature (see below) to improve your telescopes pointing accuracy.

laSt aliGnMEnt

The Last Alignment method will automatically recall the last stored index positions to continue using the alignment that was saved when the telescope was last powered down. This is a useful feature should your telescope accidentally lose power or be powered down.

NOTE: Just like with Quick-Align, you can use the Realignment feature (see below) to improve your telescopes pointing accuracy after using the Last Alignment method. To maintain a more accurate alignment over a series of observing sessions, use the Hibernate feature described later in this chapter.

rE-aliGnMEnt

The telescopes has a re-alignment feature which allows you to replace any of the original alignment stars with a new star or celestial object. This can be useful in several situations:

• Ifyouareobservingoveraperiodofafewhours,youmay

notice that your original two alignment stars have drifted towards the west considerably. (Remember that the stars are moving at a rate of 15º every hour). Aligning on a new star that is in the eastern part of the sky will improve your pointing accuracy, especially on objects in that part of the sky.

• IfyouhavealignedyourtelescopeusingtheQuick-Align

method, you can use re-align to align on actual objects in the sky. This will improve the pointing accuracy of your telescope without having to re-enter addition information.

• Ifyouhaveusedthecomputerassistedpolaralignment

method and have manually moved the mount, it may be necessary to re-align the mount for improved pointing accuracy.

To replace an existing alignment star with a new alignment star:

1. Select the desired star (or object) from the database and slew to it.

2. Carefully center the object in the eyepiece.

3. Once centered, press the UNDO button until you are at the main menu.

4. With CGEM Ready displayed, press the ALIGN key on the hand control to select Alignment Stars from the list of options

5. The display will then ask you which alignment star you want to replace. Use the UP and Down scroll keys to select the

alignment star to be replaced. It is usually best to replace the star closest to the new object. This will space out your alignment stars across the sky.

6. Press ALIGN to make the change.

objECt CataloG

Selecting an Object

Now that the telescope is properly aligned, you can choose an object from any of the catalogs in the telescope’s extensive database. The hand control has a key (4) designated for each of the catalogs in its database. There are two ways to select objects from the database: scrolling through the named object lists and entering object numbers.

Pressing the LIST key on the hand control will access all objects in the database that have common names or types. Each list is broken down into the following categories: Named Stars, Named Object, Double Stars, Variable Stars, Asterisms and CCD Objects. Selecting any one of these catalogs will display a numeric-alphabetical listing of the objects under that list. Pressing the Up and Down keys (10) allows you to scroll through the catalog to the desired object.

When scrolling through a long list of objects, holding down either the Up or Down key will allow you to scroll through the catalog more rapidly by only displaying every ﬁfth catalog object.

Pressing any of the other catalog keys (M, CALD, NGC, or STAR) will display a blinking cursor below the name of the catalog chosen. Use the numeric key pad to enter the number of any object within these standardized catalogs. For example, to ﬁnd the Orion Nebula, press the “M” key and enter “042”.

SlewingtoanObject

Once the desired object is displayed on the hand control screen, choose from the following options:

PresstheINFOKey. This will give you useful information

•

about the selected object such as R.A. and declination, magnitude size and text information for many of the most popular objects.

• Press the ENTER Key. This will automatically slew the

telescope to the coordinates of the object.

Caution: Never slew the telescope when someone is looking

into the eyepiece. The telescope can move at fast slew speeds and may hit an observer in the eye.

Object information can be obtained without having to do a star alignment. After the telescope is powered on, pressing any of the catalog keys allows you to scroll through object lists or enter catalog numbers and view the information about the object as described above.

FindingPlanets

Your telescope can locate all 8 of our solar systems planets plus the Moon. However, the hand control will only display the solar system objects that are above the horizon (or within its ﬁlter limits). To locate the planets, press the PLANET key on the hand control. The hand control will display all solar system objects that are above the horizon:

• UsetheUp and Down keys to select the planet that you wish

to observe.

• PressINFO to access information on the displayed planet.

• PressENTER to slew to the displayed planet.

+ 26 hidden pages

Celestron CGEM DX Instruction Manual

Specifications and Main Features

Frequently Asked Questions

User Manual