See product page at celestron.com for other language versions of this instruction manual.
Consultez la page produit sur celestron.com pour les autres versions linguistiques de ce manuel d’instructions
Siehe die Produktseite auf celestron.com für andere Sprachversionen dieser Bedienungsanleitung.
Cons ultare l a pagina re lativa a l prodot to su cele stron. com per le ve rsioni in al tre ling ue del pres ente manu ale di ist ruzion i.
Consulte la página del producto en celestron.com para ver las versiones en otros idiomas de este Manual de instrucciones.
With the Celestron StarSense Autoguider, using a Celestron telescope
for astroimaging has never been easier. This all-in-one accessory can
help with every aspect of telescope alignment and tracking. With your
new StarSense Autoguider (SSAG), you can:
• Automatically align your equatorial or altazimuth telescope to the night
sky in just a few minutes. Once aligned, your telescope will fi nd and
center objects with enhanced pointing accuracy.
• Guide your telescope accurately during long astroimaging exposures
without any additional alignment required (not even polar alignment).
• Quickly and accurately polar align your equatorial mount, if desired.
Please read this manual before setting up and using your StarSense
Autoguider. You can fi nd the most current version of this instruction
manual on the StarSense Autoguider product page at celestron.com.
WARNING – Never point the StarSense Autoguider at the Sun! Doing
so will damage SSAG’s image sensor. This damage is not covered under
your warranty. Keep SSAG’s cover cap on during the day.
StarSense Autoguider connects to your optical tube using one of the two
supplied brackets (i.e., the large bracket or the small bracket). Use the
large bracket with Schmidt-Cassegrain, EdgeHD, and RASA telescopes
with 5” or more of aperture (Fig. 2).
Large bracket
Large
bracket base
Fig. 2: The large bracket and base connect SSAG to Celestron Schmidt-
Cassegrain, EdgeHD, and RASA telescopes 5” or larger.
Use the small bracket with other telescopes that have a standard dovetail
base for a fi nderscope (Fig. 3).
1. Parts List
A. StarSense Autoguider with cover cap
B. Large bracket (pre-installed on StarSense Autoguider)
C. Large bracket base
D. AUX cable
E. Phillips head screws (2)
F. Large bracket base thumbscrews (2)
G. Hex key
H. Small bracket
Small
bracket
Standard
fi nder base
Fig. 3: If your telescope already has a standard fi nder base, you can use the small
bracket to mount SSAG on your telescope.
If you are using a telescope smaller than 5” in aperture, and your
telescope does not have a standard dovetail base you must purchase a
standard dovetail base from a third-party supplier.
ENGLISH | 1
If you are using the pre-installed large bracket to mount SSAG to
your telescope tube:
1. Connect the large bracket base to the telescope. (Note: Some
telescopes may already have this base installed; it is the same one
used for the 8x50 fi nderscope included with several telescopes.) If
you need to install the base, use the Phillips-head accessory screws,
which are pre-installed in the rear cell of the telescope. There are
usually two locations on the rear cell to mount the base (Fig. 4).
If you are using the small bracket, you’ll need to remove SSAG from
the large bracket fi rst. To mount SSAG with the small bracket:
1. Unthread SSAG’s front housing completely and remove it. Doing this
will expose SSAG’s optical tube (Fig. 6). Also, remove the orange front
cosmetic ring.
Front of SSAG housing
Bracket
mounting
location 1
Bracket
mounting
location 2
Fig. 4: The large bracket can be connected to the OTA in two locations on most
Celestron telescopes.
2. Remove the screws, orient the base as shown, and line up the holes in
the base with the holes in the rear cell.
3. Reinstall the screws so the base is secure. If needed, use the two
supplied Phillips head screws.
4. Loosely thread the two thumbscrews into the large bracket (Fig. 5).
Thumbscrews
Fig. 5: Install the thumbscrews into the large bracket base. These secure the large
bracket.
5. Slide the bracket onto the base until it is fully seated.
6. Tighten the thumbscrews to secure the bracket to the base.
The optional 8” CGE Dovetail Bar for mounting accessories will obstruct
SSAG’s large bracket. The CPC 800 fork arm also obstructs SSAG. For
these confi gurations, attach the base and large bracket backwards as
shown in Fig. 5a.
Orange
cosmetic ring
Fig. 6: To switch brackets, completely unthread and remove the entire front of the
SSAG housing, including the orange ring.
NOTE: When removing the front housing to install the small bracket,
you could accidentally affect SSAG’s factory focus. Keep this in
mind when you are using SSAG later. If the device is not working
correctly and you are receiving “No Stars!” error messages, you
may need to refocus. To do so, refer to the section on Focusing
later in this manual.
2. Use the hex key to loosen the socket head cap screw, which provides
the bracket’s clamping force. Then pull SSAG out of the bracket
(Fig. 7). Doing this will also remove the orange rear cosmetic ring.
Hex key
Socket head
cap screw
Rear orange
cosmetic ring
Fig. 7: Loosen the socket head cap screw. Remove SSAG from the large bracket,
including the rear orange ring.
3. Loosen the socket head cap screw on the small bracket’s clamp and
install SSAG and the orange ring into the small bracket. Orient it as
shown (Fig. 8).
Socket head cap screw
Fig. 5a: You’ll need to install the base and large bracket backwards on a CPC 800
telescope.
2 | ENGLISH
Fig. 8: Install SSAG into the small bracket as shown, then retighten the socket head
cap screw on the bracket.
4. Retighten the socket head cap screw on the small bracket’s clamp.
5. Reinstall SSAG’s front housing and the orange front ring (Fig. 9).
Fig. 9: Reinstall the front housing onto SSAG. Don’t forget the orange cosmetic ring!
6. To install SSAG into your telescope’s standard fi nderscope dovetail
base, simply insert the small bracket into the base and tighten the
thumbscrew on the base to secure it in place.
Now that you have installed SSAG, you’ll need to connect its AUX port
to one of the AUX ports on your telescope mount. Use the supplied AUX
cable (Fig. 10). If you do not have an available AUX port on your mount,
consider purchasing an optional Celestron AUX Port Splitter.
AUX port (on SSAG)
CPWI Telescope Control Software for PC
You can control your telescope and StarSense Autoguider with our
free Celestron CPWI software. To download the latest version, visit:
You’ll need CPWI version 2.5.0 or greater. Install the software and open
CPWI. Select “Start” if the opening window appears. Then, click on the
“Connection” icon in the upper left corner of the screen. If you are using a
wired c onnection to you r Celestron m ount (i.e., thr ough the hand co ntrol or
the mount i tself), sel ect “USB.” If you a re using the Sk yPortal Wi Fi Module,
select “WiFi.” CPWI should fi nd and connect to the autoguider. Once
conne cted, the SSAG ic on will appe ar in the selec tion menu on th e left side
of the screen. Select the icon to display the StarSense Autoguider menu
(Fi g . 11) .
AUX cable
AUX port (on mount)
Fig. 10: Use the supplied AUX cable to connect SSAG’s AUX port to the mount’s
AUX port.
3. Controlling Your StarSense Autoguider
There are several ways to control your StarSense Autoguider:
NexStar+ Hand Control
To use SSAG with the NexStar+ hand control that came with your
Celestron mount, you will likely need to update the hand control’s
fi rmware. You’ll need fi rmware version 5.35.XXXX or greater. To
check your fi rmware version number, press the MENU button. Use
the SCROLL and ENTER buttons to navigate to Hand Control>Get
Version Info. Use the Celestron Firmware Manager (CFM) software to
update the fi rmware if needed. You’ll fi nd the latest version of CFM here:
celestron.com/pages/drivers-and-software
You’ll need a USB cable (Type-A to Mini-B) to connect the hand control to
your PC. Refer to section 9 of this manual (page 10) for more information.
Fig. 11: When you connect your Celestron mount to your PC and launch CPWI,
you should see the StarSense AG menu among the icons on the left side
of the screen.
SkyPortal App for iOS and Android
If you use the Celestron SkyPortal WiFi Module or have a Celestron
mount with built-in WiFi (e.g., NexStar Evolution), you can use the
SkyPortal app to control your SSAG. Please refer to the Support &
Downloads section on the StarSense Autoguider page at celestron.com
for more information.
4. Using SSAG with the NexStar+
Hand Control
The NexStar+ hand control is perhaps the simplest way to control your
SSAG, as it doesn’t require an external computer. You can use the hand
control as you normally would but with SSAG’s enhanced functionality.
Auto Align
One of SSAG’s most convenient features is its ability to align your
Celestron mount to the night sky automatically. No more manually
centering stars to provide alignment references; it’s all handled
automatically.
To perform an automatic alignment using the
NexStar+ hand control:
1. Power on the mount.
2. Press ENTER.
3 a. If you have an EQ mount with home position switches, such
as the CGX or CGX-L, the hand control will prompt you to move the
mount to its home position. Press ENTER.
ENGLISH | 3
b. If you have an EQ mount without home positioning
switches, such as the Advanced VX mount, the hand control will
prompt you to manually move the mount to its index marks. To do
this, loosen the clutches and rotate the RA and DEC axes until the
index marks line up. Then retighten the clutches and press ENTER.
c. If you have an AZ mount, point the telescope toward the northern
horizon (i.e. tube positioned horizontally and pointing roughly North)
or southern horizon if you are located in the Southern Hemisphere.
Then, use the SCROLL UP and SCROLL DOWN keys to select
“Auto Align.” Press ENTER.
4. If you are using an EQ mount, you will now be asked if you would like to
polar align the mount. We recommend polar aligning before doing sky
alignment, as you will need to perform sky alignment again if you polar
align later. If you would like to polar align at this time, press the ALIGN
button. Otherwise, press ENTER to continue with sky alignment. If you
have chosen to polar align now, refer to the Polar Alignment section
on page 5.
5. Follow the onscreen prompts to input your location, local time,
and date.
- You may want to use the city database to set your location. Don’t
worry if your exact location is not in the database. Just select the
nearest city.
6. Select an alignment method. (If you are using an AZ mount, you did
this in Step 3c.) Use the SCROLL UP and SCROLL DOWN keys to
select “Auto Align.” Press ENTER.
7. The mount will begin slewing to a position where SSAG will obtain its
fi rst alignment reference. Once the mount stops slewing, SSAG will
capture an image of the sky and determine its position.
NOTE: If the telescope automatically slews to point to an area of the sky
that is locally obstructed (by buildings, trees, etc.), it will fail and
automatically slew to another point to try again.
8. The mount will slew to another position to obtain the second alignment
reference.
9. If you are using an altazimuth mount, the Auto Align process is now
complete. If you are using an equatorial mount, SSAG will slew to
a third position on the other side of the meridian to obtain a third
alignment reference.
10. After SSAG has captured two or three references, you will see “Align
Success!” on the NexStar+ LCD screen.
Your mount is now aligned. However, before it can accurately place
objects in the telescope’s fi eld of view, SSAG must determine the offset
between its own fi eld of view and that of the telescope in a process
called “center calibration.” If you have never center-calibrated SSAG and
your telescope, the hand control will prompt you to do so immediately
after initial alignment. Refer to the “Center Calibration” section later in
this manual. If you have performed a center calibration previously, the
telescope is now ready to fi nd and place objects near the center of the
fi eld of view.
Manual Align
You may consider using the Manual Align option if you have many
obstructions at your observing location, such as buildings, tree s, or power
lines. Manual Align works like Auto Align but allows you to manually slew
the telescope to clear areas of the sky to obtain the alignment references.
Because the telescope won’t automatically slew to positions blocked by
obstructions, the overall alignment process is quicker.
To perform a “manual” alignment using the
NexStar+ hand control:
1. Follow steps 1 through 5 in the Auto Align section above.
2. When the hand control prompts you to select an alignment method,
use the SCROLL UP and SCROLL DOWN keys to select “Manual
Align” and press ENTER.
3. The hand control will prompt you to slew the telescope to a clear area
of the sky using the direction buttons. When the telescope is pointing
4 | ENGLISH
to a clear area of the sky, press ENTER. SSAG will capture an image
to use as an alignment reference.
NOTE: For best results with EQ mounts, do not slew the telescope
towards the North (or South) poles to capture alignment
references.
4. The hand control will prompt you to manually slew the telescope to
another clear area of the sky.
a. For altazimuth mounts, slew the mount in both axes, making
sure SSAG is pointing at least 60° away from its fi rst alignment
point. Press ENTER. The Manual Align is now complete. Skip to
St ep 7.
b. For equatorial mounts, slew the mount to another clear area
of the sky. This location must be on the same side of the meridian
as the fi rst area you chose. Press ENTER.
5. After completing the fi rst two alignment references, the hand control
will display “Add Calib Star?” We strongly recommend adding a third
alignment reference for the best overall pointing accuracy across the sky.
a. Choose “No” to end the alignment with only two references. This
alignment may provide acceptable pointing accuracy in many
cases, especially if Precise GoTo is on (as explained later in this
manual). Skip to Step 7.
b. Choose “Yes” to add a third alignment reference. The telescope
will automatically slew to the other side of the meridian.
6. With the telescope now on the opposite side of the meridian from the
fi rst two alignment points, the hand control will prompt you to choose
a third clear area of sky. Use the direction keys to slew to a clear area
of sky on this side of the meridian and press ENTER.
7. You will see “Align Success!” on the NexStar+ LCD screen when
completed.
Your mount is now aligned. However, before it can accurately place
objects in the telescope’s fi eld of view, SSAG must determine the offset
between its own fi eld of view and that of the telescope in a process
called “center calibration.” If you have never center-calibrated SSAG and
your telescope, the hand control will prompt you to do so immediately
after initial alignment. Refer to the “Center Calibration” section later in
this manual. If you have performed a center calibration previously, the
telescope is now ready to fi nd and place objects near the center of the
fi eld of view.
User Auto Align
This alignment method only works after you have performed at least one
Manual Auto Align. When you select User Auto Align, the telescope
automatically moves to the alignment points you defi ned during the
previous Manual Auto Align. It’s a handy option if you set up in the same
location most nights and there are signifi cant obstructions at the site.
To perform a User Auto Align, follow the instructions for Auto Align above
but choose “User Auto Align” as the alignment method. Once initiated,
the telescope will automatically slew to the fi rst alignment point in the
prior Manual Auto Align. It will then proceed to the other user-defi ned
points to complete the alignment.
Last Align
If you leave your telescope set up in a single location, such as a home
observatory, Last Align is a convenient choice. You can only use this
method if you do not slew or otherwise move the telescope in any way
after powering it off. This alignment method uses the previous SSAG
alignment data stored in the hand control. No further action is required.
Quick Align
This procedure aligns the mount using only the time/date/location
information. It assumes that equatorial mounts are perfectly polar aligned
and altazimuth mounts are level and pointing North. Quick Align does not
use the SSAG device.
We don’t usually recommend this alignment method. But if your mount
is already well polar aligned, this option may provide accurate enough
pointing and tracking with no further alignment required. It can also be
handy when you are searching for planets in twilight.
EQ North Align and EQ South Align
(AZ mounts only)
If you are using an AZ mount on an equatorial wedge, choose “EQ North
Align” in the Northern Hemisphere or “EQ South Align” in the Southern
Hemisphere. Follow the steps for Auto Align described above, but now
consider your telescope an EQ mount instead of an AZ mount.
Center Calibration
Center calibration aligns SSAG’s fi eld of view with that of your telescope.
You’ll generally only need to center-calibrate the fi rst time you use SSAG
with a new telescope tube. However, you may need to center-calibrate
again if you remove the bracket base from the telescope and then reinstall
the bracket. If you only remove SSAG and its bracket, leaving the bracket
base on the telescope, you should not need to center-calibrate again.
Before doing a center calibration, align the telescope to the night sky
using one of the above procedures. If you have not center-calibrated
previously, SSAG will automatically initiate a center calibration after sky
alignment.
To perform a center calibration:
1. Press the MENU button and use the SCROLL keys to select “SSAG.”
Press ENTER. Use the SCROLL keys to select “Center Calibrate” and
press ENTER.
NOTE: If you have never center-calibrated SSAG, the NexStar+ hand
control will automatically start the center calibration process after
alignment.
2. Next, use the SCROLL keys to select either Named Stars or Solar
System Objects (i.e., planets) to use for center calibration. Press
ENTER. Scroll through the list of stars or planets and select one
clearly visible from your location. Press ENTER.
• If you are unsure where the object you chose is in the night sky,
don’t worry. The telescope will point close to the object in the next
step. You can use the telescope as a guide to determine which star
or planet you are using to center-calibrate. Remember that named
stars and planets are among the brightest objects in the night sky.
• For best results with an EQ mount, choose stars that are close to the
celestial equator (i.e., away from poles).
3. The telescope will slew to the star or planet you chose. Depending
on the offset between SSAG’s fi eld of view and the telescope’s, the
object may or may not be in the telescope’s fi eld of view. In any case,
the telescope should generally be pointing toward the object.
4. The NexStar+ hand control will ask you to center the object in the fi eld
of view of the fi nderscope. Use the direction buttons on the keypad
to do this. Don’t worry about fi ne centering yet—that happens in the
next step. For now, roughly center the object in the fi eld of view of the
fi nderscope and press ENTER.
• If the star is not within the fi nderscope’s fi eld of view, slew the
telescope manually until it is.
• If you’re not using a fi nderscope, use your widest fi eld eyepiece in
the telescope for this step. If the object is not in the fi eld of view,
try sighting down the length of the telescope tube to point to the
object.
5. The NexStar+ hand control will prompt you to center the object in
the eyepiece’s fi eld of view. This is the fi ne-centering step. Make sure
there is a high-powered eyepiece in the telescope. Use the direction
buttons on the keypad to center the object. For the best results, use
the up and right direction keys last. When you fi nish, press ALIGN.
6. SSAG will perform the center calibration and return the message
“Center Calib Success.”
Once you’ve completed Auto Align and Center Calibration, you can
command the telescope to accurately place any celestial object you
choose within the telescope’s fi eld of view.
Autoguiding
If you are imaging an object with a camera, you can use SSAG to
accurately autoguide the telescope through the exposure.
After you complete the alignment and center calibration, you can initiate
autoguiding by pressing the MENU button and using the SCROLL keys
to select “SSAG.” Press ENTER. Then use the SCROLL keys to choose
“Guiding” and press ENTER.
The hand control’s LCD will display a screen like Fig. 12. The numbers
on the top line represent the right ascension (R A) RMS tracking error,
and the numbers on the bottom line represent the declination (Dec) RMS
tracking error in arcseconds. The +/- symbols to the right of the RA and
Dec RMS tracking errors indicate the direction of the previous tracking
command on that axis. The “s” number is the number of stars SSAG is
using for guiding. The “Q” number represents the quality of the guiding,
which is essentially a measurement of the local seeing conditions—zero
is poor while 100 is ideal. The blinking asterisk next to the Q number
indicates that the hand control is receiving guiding commands from
SSAG.
SSAG will continue guiding indefi nitely. When you are ready to stop
guiding, press the BACK button. (While autoguiding, none of the hand
control’s buttons will work except the BACK button.)
Fig. 12: While autoguiding with the NexStar+ hand control, you’ll see the guiding
error for both axes on the LCD.
Polar Alignment
Although your equatorial mount does not need to be accurately polar
aligned to use SSAG, SSAG can help you achieve a very accurate polar
alignment. A precise polar alignment slightly improves overall pointing
accuracy—but only by a few arcminutes. If you choose to polar align, do
so before sky alignment and center calibration. Keep in mind that only
equatorial mounts or AZ mounts using EQ wedges can be polar aligned.
NOTE: These instructions explain how to perform the polar alignment
procedure in the Northern Hemisphere. If you are in the Southern
Hemisphere, always point your mount due South instead of due
North.
To perform a polar alignment with SSAG:
1. Roughly polar aligning your mount fi rst will make the entire process
quicker and easier. Once you are roughly aligned, you can achieve an
accurate polar alignment using only the mount’s altitude and azimuth
fi ne adjustment knobs.
a. Make sure the mount is reasonably level. If your mount has a
bubble level built in, use that for reference.
b. Adjust the altitude of the mount so that the mount’s latitude scale
indicates roughly the same latitude as your observing site.
c. Lift and rotate the entire tripod and mount so that the right
ascension (RA) axis points approximately due North. The
ENGLISH | 5
mount’s position doesn’t need to be perfect. Aim within about
5° due North so the mount is within the range of the mount’s
azimuth fi ne adjustment knobs. Use a free compass app for your
smartphone if you need help fi nding North.
d. If you loosened the altitude or azimuth adjustment knobs during
rough polar alignment, make sure they are retightened before
continuing.
2. Press the MENU button and use the SCROLL keys to navigate to the
SSAG menu. Then press ENTER.
3. Use the SCROLL keys to select “Polar Align.” Press ENTER.
4. The hand control will ask you to slew the telescope to a clear area
of the sky. Use the hand control’s direction keys to point to a clear
location. Press ENTER.
• The telescope will slew from West to East for about 50° during the
polar alignment process. Try to choose a clear area that provides
a clear path.
5. The telescope will slew from West to East to obtain polar alignment
references. This will take a few minutes.
6. When the telescope stops slewing, the hand control will display
“Adjust AZM.” Press ENTER. The LCD will now show the AZM and
ALT polar alignment errors.
7. If your mount has an azimuth axis lock knob or locking screws, loosen
them before adjusting the azimuth.
8. Use the mount’s azimuth fi ne adjustment knobs to adjust the
mount’s azimuth (left-to-right) positioning slowly. As you make these
adjustments, the AZM error will increase or decrease. Continue
adjusting until the AZM error is below two arcminutes. Press ENTER.
• Do not adjust the altitude of the mount! You will make altitude
adjustments in the next step.
• Make the adjustments slowly so SSAG can track them. If you
adjust too quickly and SSAG loses track, you’ll need to restart the
entire polar alignment process.
9. The hand control will now display “Adjust ALT.” Press ENTER.
10. If your mount has altitude axis lock knobs, loosen them before
adjusting altitude.
11. Use the mount’s altitude fi ne adjustment knobs to adjust the mount’s
altitude (up-and-down) positioning slowly. As you make these
adjustments, the ALT error will increase or decrease. Continue
adjusting until the ALT error is below two arcminutes. Press ENTER.
• Do not adjust the azimuth of the mount.
12. The hand control will now ask, “Fine Adjust AZM?”
a. If you wish to make additional adjustments to the azimuth, use the
SCROLL keys to select “Yes” and press ENTER. Adjust until the
error is less than two arcminutes, and press ENTER.
b. If you do not want to make further adjustments, use the SCROLL
keys to select “No” and press ENTER.
13. Congratulations! You have successfully polar-aligned your mount. If
your mount has altitude or azimuth locking knobs or screws, tighten
them fi rmly. For best results, do sky alignment after polar alignment.
If you have already done a sky alignment, then we recommend power
cycling and performing sky alignment again.
NOTE: Don’t attempt to adjust the polar alignment to better than two
arcminutes on each axis. Doing so will be diffi cult and will not
provide additional pointing or tracking benefi ts. In many cases,
autoguiding performance may actually be better with a slight polar
alignment error.
Other Functionality
You can access all the additional options below by pressing the MENU
button, using the SCROLL keys to select “SSAG,” and pressing ENTER.
Refer to Fig. 13 for the SSAG menu tree.
SSAG
PRECISE GOTO
PLAT E SOLVE
CENTER CALIBRATE
POLAR ALIGN
GUIDING
VERSION
SETTINGS
FACTORY RESET
Fig. 13: The SSAG menu tree in the NexStar+ hand control.
Precise GoTo
Precise GoTo uses SSAG to more accurately center objects in the
fi eld of view. When this option is enabled, the telescope mount uses
its internal alignment model to fi nd and center the object as usual; this
should generally place the object somewhere in the fi eld of view. Then
SSAG takes over, making fi ne corrections to the centering, signifi cantly
improving the overall pointing accuracy. When you are using SSAG,
Precise GoTo is enabled by default, so you do not need to initiate a
Precise GoTo here. However, if you have turned Precise GoTo off (see
Settings section below), you can initiate a Precise GoTo to a specifi c
object from this menu selection.
Plate Solve
When you choose this option, SSAG will capture an image and plate
solve. The hand control will display the center coordinates (RA and Dec)
to which the telescope is pointing in the sky.
Version
Selecting this option displays the current version number of SSAG’s
internal software.
• To view the NexStar+ hand control fi rmware version, select the “Version”
option from MENU>Utilities.
Settings
Use Precise GoTo – This setting allows you to enable or disable
automatic Precise GoTo after every slew. Precise GoTo is on by default for
the best pointing accuracy. However, this feature causes the telescope
to take slightly longer to center objects. We recommend that most users
leave Precise GoTo on.
Factory Reset
A factory reset power cycles SSAG and clears the device of any previous
center calibration data. When you turn on SSAG after a Factory Reset,
it will automatically initiate a new center calibration after sky alignment.
5. Using SSAG with CPWI
6 | ENGLISH
If you already use a PC to control your telescope (e.g., for astroimaging),
Celestron’s free CPWI software is a great way to control SSAG. Its
intuitive user interface makes accessing all of SSAG’s features easy.
StarSense Alignment
After you connect CPWI to your Celestron mount and SSAG as
described previously, the Alignment window will appear (Fig. 14) so you
can select a method to align your mount with the night sky. But fi rst,
check the date, time, and location near the top of the window. If you
notice any mistakes, click the “Set Time” or “Set Location” buttons to
adjust.
Fig. 14: The SSAG alignment window in CPWI.
If you are using an AZ mount with an EQ Wedge, select the “EQ Wedge”
option that appears in the top right of the Alignment window. Selecting
this will treat the AZ mount as an EQ mount.
For completely automatic alignment, choose “StarSense Alignment,”
then press the “Begin Alignment” button. The Pointing Model Information
will appear (Fig. 15). In the “Home Switches” section, CPWI asks, “Is
the mount ready to move to the home switches?” If your mount has home
switches (e.g., CGX and CGX-L), click “Ready,” and the telescope will
move to its home switches. If your mount does not have home switches
but has index marks, manually move the telescope to its index marks.
If you are using an AZ mount, CPWI will ask you to point your telescope
toward the Northern horizon (i.e. tube horizontal and pointing North).
Point the telescope to the southern horizon if you are in the Southern
Hemisphere. Use the Mount Slew Controls window that appears
onscreen to do this. You don’t need to be precise with this step; it’s only
an initial position for the alignment routine.
polar align later by selecting the “Polar Align Mount” option from the
StarSense AG menu.
NOTE: Remember, in many cases, you will not need to accurately polar
align your mount to use SSAG, including for autoguiding.
After polar alignment, the window will display “StarSense Alignment”
and prompt you to select an alignment option (Fig. 16).
Fig. 16: StarSense Alignment options in CPWI.
Auto Four Points
Auto Four Points is the most automated alignment choice. SSAG will
automatically slew to four points in the sky to achieve sky alignment. If it
points to an obstruction or otherwise fails to determine its position, the
telescope will simply slew to another point in the sky to obtain another
alignment reference.
Custom Points
Custom Points allows you to defi ne points in the sky where the telescope
slews for alignment. It’s a good choice if your observing site has local
obstructions because you can defi ne the alignment points so that the
telescope steers clear of them. If you choose this option, the StarSense
User Interface Auto Alignment Creator window will appear (Fig. 17).
Fig. 15: Pointing Model Info window in CPWI.
If you have not center calibrated your SSAG previously, you should do
so before sky alignment when prompted by CPWI. Unlike the NexStar+
hand control, CPWI requires you to perform center calibraton before sky
alignment. Otherwise, you will need to perform the sky alignment again.
Please refer to the “Center Calibration” section on page 8.
Next, if you are using an EQ mount or AZ mount on an EQ wedge, CPWI
will ask if you would like to polar align. (If you want to polar align your
mount, now is the best time. If you polar align after sky alignment, you’ll
need to perform sky alignment again.) To polar align, click “Yes” and
follow the instructions in the Polar Align section on page 8. If you choose
not to polar align, click “No” to move on to sky alignment. You can always
Fig. 17: Auto Alignment Creator window in CPWI.
Click within the chart to select alignment points in the sky. You’ll fi nd the
cardinal directions on the perimeter of the chart. The interior of the chart
goes from 0° altitude (i.e., the horizon) at the edge to 90° (i.e., zenith)
at the center. You can choose more than four alignment points if you
wish. For the best results, choose points spaced widely apart and avoid
ENGLISH | 7
points near the poles for EQ mounts. After selecting alignment points,
click “Complete” in the bottom left of the window. Before CPWI begins
the alignment, it will ask if you want to save your user-defi ned alignment
points. If you do, you can use the .sua fi le later with the “Load Custom
Points” option.
Load Custom Points
Once you have defi ned “Custom Points” as described above, you can
choose this option to use them again. Select the .sua fi le you created
previously, and alignment will automatically begin.
Manual Slewing
With this alignment option, you use the Mount Slew Controls window
to manually slew SSAG to a clear area of the sky and click “Solve Here”
to obtain an alignment reference. Repeat the process four times, and
alignment is complete. This is the least automated choice, but it can be
helpful if your observing site has obstructions or the sky is partly cloudy.
For best results, use four alignment points that are as widely spaced as
possible and avoid points near the poles for EQ mounts.
Adding Additional Alignment References
After alignment, you can see the information about the mount’s generated
pointing model, including the RMS error, the total number of points in the
alignment model, and the calculated polar alignment error.
You can add additional alignment references throughout the night by
selecting an object in the planetarium view, clicking on it, and choosing
“Model.” The mount will slew to the object’s location, and SSAG will
add the alignment reference to the mount’s pointing model. Pointing
accuracy should be quite good with only four points, but it will generally
increase with each alignment reference you add.
If you have never performed a center calibration with your telescope and
SSAG, CPWI will prompt you to do so after sky alignment.
Center Calibrate
Center calibration aligns SSAG’s fi eld of view with that of your telescope.
You’ll generally only need to center-calibrate the fi rst time you use SSAG
with a new telescope tube. However, you may need to center-calibrate
again if you remove the bracket base from the telescope and then reinstall
the bracket. If you only remove SSAG and its bracket, leaving the bracket
base on the telescope, you should not need to center-calibrate again.
If you have not center-calibrated previously, SSAG will automatically
initiate a center calibration before sky alignment. If you want to centercalibrate later, choose “Center Calibrate” from the StarSense AG menu.
To do a center calibration:
1. Select an object in the SkyViewer planetarium screen by clicking
on it. Choose a bright star or planet that is clearly visible from your
observing location.
2. The telescope will now slew to the selected object. Depending on the
offset between SSAG’s fi eld of view and the telescope’s, the object
may or may not be in the telescope’s fi eld of view. In any case, the
telescope should be pointing toward the object.
3. CPWI will prompt you to center the object in the fi eld of view of the
telescope’s eyepiece. You can use the onscreen Mount Slew Controls
window. When you are fi nished, click “Centered” in the Pointing
Model Information window.
• If the star is not within the fi eld of view of the fi nderscope, slew
manually until it is.
• If you are not using a fi nderscope, use your widest-fi eld eyepiece
to fi nd the object instead. If the object is not in the eyepiece’s
fi eld of view, sight down the length of the telescope tube to point
it to the object.
• For fi nal centering, use a high-powered eyepiece.
• When centering the star in the telescope’s fi eld of view, use the up
and right direction keys last.
8 | ENGLISH
4. SSAG will perform the center calibration and return the message
“Center Calib Success.”
Once you’ve completed Auto Align and Center Calibration, you can
command the telescope to accurately place any celestial object you
choose within the telescope’s fi eld of view.
Polar Alignment
Although your EQ mount (or AZ mount on EQ wedge) does not need
to be polar aligned to use SSAG, SSAG can help you achieve a very
accurate polar alignment. A precise polar alignment slightly improves
overall pointing accuracy—but only by a few arcminutes. If you choose to
polar align, do so before sky alignment. If you wish to polar align later, you
can select the “Polar Align Mount” option in the SSAG menu.
NOTE: These instructions explain how to perform the polar alignment
procedure in the Northern Hemisphere. If you are in the Southern
Hemisphere, always point your mount due South instead of due
North.
To perform a polar alignment with SSAG through CPWI:
1. Roughly polar aligning your mount fi rst will make the entire process
quicker and easier. Once you are roughly aligned, you can achieve an
accurate polar alignment using only the mount’s altitude and azimuth
fi ne adjustment knobs.
a. Make sure the mount is reasonably level. If your mount has a
bubble level built in, use that for reference.
b. Adjust the altitude of the mount so that the mount’s latitude scale
indicates roughly the same latitude as your observing site.
c. Lift and rotate the entire tripod and mount so that the right
ascension (RA) axis points approximately due North. The
mount’s position doesn’t need to be perfect. Aim within about
5° due North so the mount is within the range of the mount’s
azimuth fi ne adjustment knobs. Use a free compass app for your
smartphone if you need help fi nding North.
d. If you loosened the altitude or azimuth adjustment knobs during
rough polar alignment, make sure they are retightened before
continuing.
2. Manually slew the telescope to an initial start position using the Mount
Slew Controls window.
• The telescope will slew from West to East for about 50° during the
polar alignment process. Try to choose a clear area that provides
a clear path.
3. Click “Begin” in the SSAG Polar Alignment section of the Pointing
Model Information window. The mount will slew East, stopping about
every 10° to obtain a polar alignment reference.
4. After SSAG has obtained its polar alignment references, it will display
the azimuth axis adjustment window (Fig. 18). Slowly fi ne-adjust your
mount’s azimuth until the “Azm Error” is less than two arcminutes.
• If the mount has azimuth axis locks, loosen them fi rst.
• Make the adjustments slowly so SSAG can track them. If you
adjust too quickly and SSAG loses track, you’ll need to restart the
entire polar alignment process.
Fig. 18: Azimuth Axis Adjustment window during polar alignment in CPWI.
5. Click “Next Axis” when you are done making adjustments to the
azimuth. The Altitude axis adjustment window will appear (Fig. 19).
Fig. 19: Altitude Axis Adjustment window during polar alignment in CPWI.
6. Slowly fi ne-adjust your mount’s altitude until the “Alt Error” is less than
two arcminutes.
• If the mount has altitude axis locks, loosen them fi rst.
7. If you would like to readjust the azimuth axis, click “Next Axis.”
Otherwise, click “Finish.”
8. Congratulations! You have successfully polar-aligned your mount. If
your mount has altitude or azimuth locking knobs or screws, tighten
them fi rmly. For best results, do sky alignment after polar alignment.
If you have already done a sky alignment, then delete the current
alignment from the Alignment menu and perform sky alignment again.
NOTE: Don’t attempt to adjust the polar alignment to better than two
arcminutes on each axis. Doing so will be diffi cult and will not
provide additional pointing or tracking benefi ts. In many cases,
autoguiding performance may actually be better with a slight polar
alignment error.
Autoguiding
After sky alignment is complete, SSAG is ready for autoguiding. Simply
slew to the object you wish to image, then turn on the “Guiding Enabled”
option i n the SSAG menu. The S SAG will then provi de guiding cor rections
to your mount automatically. To see the autoguiding corrections, you
can select “Guider Graphs” from the SSAG menu. A graph will appear
showing the error corrections over time.
NOTE: Keep in mind that overall autoguiding performance relies on many
different factors, including the load on the mount, your mount’s
balance (i.e., your mount must be well balanced along both axes),
and local seeing conditions.
You’ll need to turn guiding on again after slewing to a new object, as the
SSAG needs to recalibrate itself before it can begin guiding on the new
object.
Dithering
In the SSAG menu under Settings (Fig. 20), CPWI offers dithering
options to use with your camera control software when autoguiding.
Dithering moves the telescope very slightly between exposures, helping
to make image processing noise reduction techniques more effective.
You’ll need to connect your camera software to CPWI via the ASCOM
driver built into CPWI to use this feature. After you enable dithering in
CPWI, you can set the minimum dithering distance (from 0 to 10”) and
the maximum dithering distance (20” to 50”). For some camera control
software, you may also need to enable “PHD Mode” in the SSAG menu.
Fig. 20: You can enable dithering, adjust parameters, and manually adjust guide rates in
the Settings section.
Guide Rate
Normally, you do not need to manually adjust the guide rates for
autoguiding (i.e., the distance the mount moves with each SSAG guide
command). However, suppose your mount is not autoguiding well in one
or both axes. In that case, try manually adjusting the guide rates from
the Settings section of the SSAG menu (Fig. 20). First, turn on Manual
settings for Guide Rate, then adjust the guide rate for each axis using the
sliders. Use trial and error to determine your mount’s best manual guide
rate settings.
Other Functionality
Live View
The Live View window displays a live readout from SSAG’s image sensor.
Its primary purpose is to aid in focusing SSAG’s lens (see the section on
Focusing later in this manual), but it can also be interesting to see what
SSAG is seeing. Note the sharp stars across the fi eld of view due to the
excellent optical design of the lens.
To see the Live View, you’ll need to connect SSAG directly to your
PC using a USB Type-A to USB Type-C cable (not supplied). This is
because the AUX interface cannot support the transfer of images. You’ll
also need to install the SSAG driver on your computer. You’ll fi nd it in the
Support & Downloads section of the StarSense Autoguider (#94008)
product page at celestron.com.
Once you install the driver and connect SSAG with the USB cable,
the Live View window will display the current view from SSAG’s image
sensor. There are no controls for the Live View. SSAG automatically
adjusts exposure and gain to obtain the best images.
NOTE: You should still connect SSAG to the mount via AUX while it is
connected to the PC via USB for Live View.
Precise GoTo
Precise GoTo uses SSAG to more accurately center objects in the
fi eld of view. When this option is enabled, the telescope mount uses
its internal alignment model to fi nd and center the object as usual; this
should generally place the object somewhere in the fi eld of view. Then
SSAG takes over, making fi ne corrections to the centering, signifi cantly
improving the overall pointing accuracy. When you are using SSAG,
Precise GoTo is enabled by default. If you want to turn this feature off,
you can do so from the StarSense AG menu.
Version
Selecting this option displays the current version of SSAG’s fi rmware.
ENGLISH | 9
Factory Reset
A factory reset power cycles SSAG and clears the device of any previous
center calibration data. When you turn on SSAG after a Factory Reset,
it will automatically initiate a new center calibration after sky alignment.
6. Focusing
Technicians at the factory have focused your StarSense Autoguider, and
it should not need further adjustment. However, if you fi nd that SSAG is
not working as it should (e.g., reporting “No Stars!” when there are plenty
of stars visible in the sky), you should check the focus.
To focus StarSense Autoguider:
1. Follow the process outlined above to access the Live View in CPWI.
2. If you are focusing during the day, point SSAG at an object at least a
quarter mile away. If you are focusing at night, point SSAG at a bright
star. You should see an image onscreen.
NOTE: If you are attempting to focus during very bright daytime conditions,
try adding a 2” neutral density fi lter to dim the view. Refer to the
Using Filters section later in this manual for more details.
3. If the focus is sharp, you are done. If not, remove SSAG’s front cover
by grasping it and rotating it counterclockwise until it comes off
(Fig. 21). Only remove the front cover, not the entire front of the
housing.
Front CoverFocus Lock Ring
The status ring has three modes:
Steady on: SSAG is receiving power and idle.
Quick pulsing: SSAG is calculating a plate solve.
Pulse: SSAG has executed a guide correction during autoguiding.
Constant blinking that never stops: Contact Celestron Technical
Support at celestron.com/pages/technical-support
LED Ring
Fig. 23: The LED ring indicates SSAG’s status at a glance.
8. Using Filters
SSAG’s front housing is threaded to accept standard 2” fi lters (Fig. 24).
The most helpful fi lter to pair with your SSAG is an IR-pass fi lter that
blocks most visible wavelengths (400-700nm) but passes wavelengths
above 700nm. With this fi lter, you can align your telescope with SSAG
during twilight. Even though you won’t be able to see stars with your
eyes, SSAG will detect the near-infrared wavelengths and align your
telescope before it even gets dark! A 2” neutral density fi lter or Moon
fi lter can reduce excessive brightness when adjusting SSAG’s focus
during the day.
Fig. 21: Only remove the front cover, not the entire front of the housing.
4. Loosen the focus lock ring (Fig. 22).
Focus lock ring
Fig. 22: Loosen the lock ring when making focus adjustments, then fi rmly
retighten when focused.
5. Rotate the optics clockwise by a quarter- to half-turn to see if
focus improves. If it does, continue rotating until the focus is as
sharp as possible. If the focus does not improve, rotate the optics
counterclockwise until the focus improves.
6. When you see a sharp image, retighten the lock ring and reinstall
SSAG’s front cover. If desired, you can now disconnect SSAG from
the PC’s USB port.
7. Status LED Ring
Toward the rear of the SSAG enclosure, you’ll fi nd the LED status ring
(Fig. 23). The status ring illuminates when you connect SSAG to a
Celestron mount that is powered on. The ring provides “at a glance”
status messaging for SSAG.
2” Filter
Fig. 24: You can mount standard 2” fi lters onto the front of SSAG.
9. Updating SSAG’s Internal Software
with CFM
Our engineers are constantly working on upgrades and improvements to
our products, so we recommend periodically checking for SSAG internal
software updates at celestron.com/CFM. If a new SSAG software
update is available, you can download and install it with the Celestron
Firmware Manager (CFM) software. Follow these steps to update
SSAG’s software:
1. Set up as you usually would, with the NexStar+ hand control and
SSAG plugged into the mount’s AUX ports.
2. Power on the mount.
3. Connect the USB port on the bottom of the hand control to your PC.
You’ll need a USB Type-A to USB Mini-B cable (not supplied). The
computer should recognize the mount.
10 | ENGLISH
4. Run CFM. It should fi nd the hand control and the StarSense
Autoguider.
5. Click the Update button in CFM. CFM will install any available updates
for both SSAG and the hand control.
10. Updating SSAG’s Internal Software
and Live View via Web Interface
Alternatively, you can update SSAG’s software directly via USB. This
method does not use CFM and does not update the hand control. If any
new fi rmware is available, you’ll fi nd it as a .swu fi le on the StarSense
Autoguider (#94008) page at celestron.com. To install the fi le, you’ll
need a USB Type-A to USB Type-C cable (not supplied) and the
SSAG PC driver, also available on the StarSense Autoguider page at
celestron.com.
Follow these steps to update SSAG’s software:
1. Install the SSAG driver on your PC.
2. Connect SSAG to your PC via the USB cable. After about 10 seconds,
SSAG’s LED ring will illuminate, indicating it is receiving power via
USB.
3. Open a web browser on your computer and enter
http://169.254.54.1/ to launch the SSAG web
interface page (Fig. 25).
4. For the most accurate Precise GoTo functionality, polar align your
mount. Precise GoTo will still work well if your mount is not polar
aligned, but overall accuracy will be slightly reduced—typically by
several arcminutes.
5. For the best guiding performance, disable all backlash compensation
and periodic error correction (PEC) in the hand control or CPWI. This
prevents any confl icts between the SSAG’s guide commands and
backlash/PEC settings.
6. SSAG has a built-in lens shade that will help prevent dew from forming
on its optics. Under heavy dew conditions, however, you may consider
adding a third-party heater strip along with a Celestron Smart
DewHeater Controller to keep dew off the SSAG’s lens.
7. If you are using a USB cable to connect SSAG to your PC, make sure
it is a high-quality cable. If you have trouble connecting to SSAG via
USB, try another USB cable or another USB port on your computer.
8. When autoguiding with CPWI on a PC, you can try connecting the
PC directly to SSAG’s USB-C port (with SSAG still connected to the
mount via the AUX cable). This may improve performance because the
USB-C port handles autoguiding commands faster than the AUX port
can.
12. Specifi cations
LENS
DESIGN Double-Gauss
CLEAR APERTURE 31mm
EFFECTIVE APERTURE 28mm
FOCAL LENGTH 120mm
EFFECTIVE FOCAL RATIO f/4.3
NUMBER OF ELEMENTS 4
COATINGS Fully multi-coated
Fig. 25: Alternatively, you can update SSAG’s fi rmware via the web interface. You’ll
also be able to access Live View from here.
4. Select “Software Update.”
5. Drag and drop the downloaded .swu fi le as directed. SSAG’s software
will update.
You can also access the SSAG Live View from this web interface. You’ll
have controls to change from automatic to manual camera settings and
can even capture an image (TIFF format) here.
11. Troubleshooting and Tips
1. If you continually get the “No Stars!” error message during platesolving when the sky is clear, try refocusing SSAG.
2. If the Moon is high and bright in the sky, SSAG may have trouble plate-
solving within a few degrees of the Moon due to the intense glare. You
may receive a “No Stars!” error message.
a. If there is a light haze in the sky, SSAG may have trouble plate-
solving even farther away from the Moon.
b. An IR-pass fi lter can help reduce the Moon’s glare.
3. For the best overall performance, we recommend leveling your tripod.
SSAG will still work with a tripod that is not level, but its pointing
accuracy will be somewhat diminished.
CMOS IMAGE SENSOR
CMOS IMAGE SENSOR Sony IMX290LLR, monochrome,
back-illuminated
SENSOR SIZE 6.46mm diagonal
PIXEL SIZE 2.9μm x 2.9μm
NUMBER OF EFFECTIVE PIXELS 2.13 M
ONBOARD COMPUTER
®
PRIMARY ARM
SECONDARY ARM
CORE 2x Cortex® -A53 up to 1.4 GHz
®
CORE 1x Cortex-M7 up to 600 MHz
RAM 512 MB
ROM 4 GB
GPU GC7000UltraLite
OPERATING TEMPERATURE -25°C to 85°C
PORTS
AUX: For connection to Celestron mounts
USB-C For PC connection to focus, see Live View,
and update fi rmware
HOUSING
HOUSING Aluminum with plastic covers, threads for
2 ” fi l t e r s
ENGLISH | 11
FCC NOTE: This equipment has been tested and found to comply with the limits for a Class
Inverkehrsbringer und Service für Deutschland und Österreich:
Baader Planetarium GmbH – Zur Sternwarte - 82291 Mammendorf – Tel.: 08145/80890 - service@celestron-deutschland.de
B digital device, pursuant to part 15 of the FCC Rules. These limits are designed to provide
reasonable protection against harmful interference in a residential installation. This equipment generates, uses, and can radiate radio frequency energy and, if not installed and used in
accordance with the instructions, may cause harmful interference to radio communications.
However, there is no guarantee that interference will not occur in a particular installation. If
this equipment does cause harmful interference to radio or television reception, which can be
determined by turning the equipment off and on, the user is encouraged to try to correct the
interference by one or more of the following measures:
• Reorient or relocate the receiving antenna.
• Increase the separation between the equipment and receiver.
• Connect the equipment into an outlet on a circuit different from that to which the receiver
is connected.
• Consult the dealer or an experienced radio/TV technician for help.
Product design and specifi cations are subject to change without prior notifi cation.
This product is designed and intended for use by those 14 years of age and older.