Celestron CGEM II Computerized Equatorial Mount and Tripod

A 40 lb capacity GoTo mount for 8" to 11" SCTs and serious imaging

The Celestron CGEM II Computerized Equatorial Mount is the middle of Celestron's German equatorial line, between the Advanced VX and the CGX. Celestron designed it to carry its larger Schmidt-Cassegrains, up to the 11", for visual observing and astrophotography. It comes with the tripod, a 17 lb counterweight and the NexStar+ hand control, so you add a telescope and power and you're ready to go. It's a good fit if you've outgrown an Advanced VX or want one mount that will handle an 8" to 9.25" EdgeHD for years.

Key specs: 40 lb (18 kg) payload, not counting counterweights · dual CG-5 (Vixen) and CGE (Losmandy-style) saddle · 15°–70° latitude range · DC servo motors, 9 slew speeds · permanent PEC and autoguider port · 12V DC, 3.2A · 40 lb (18.1 kg) head, 78 lb (35.4 kg) full kit

The CGEM II is on display in our Denver store, so you can see it in person before you buy.

What you can see and image

• Galaxies with an SCT or EdgeHD: the Whirlpool, Sombrero and Pinwheel Galaxies, the Leo Triplet and M81/M82, where 2,000mm or more of focal length pays off.
• Planetary nebulae and small targets: the Ring, Dumbbell, Cat's Eye and Owl Nebulae, and globular clusters such as M13 and M3.
• The planets and Moon: Jupiter, Saturn and Mars at high power, with smooth tracking for planetary video.
• Wide nebulae with a refractor or RASA: the Orion, Rosette, North America and Veil Nebulae.

Setting it up

Set the tripod up with one leg pointing north, level it with the height marks on the legs, then add the mount head, counterweight bar and counterweight. The saddle takes both narrow CG-5 (Vixen) and wide CGE (Losmandy-style) dovetails, so most telescopes slide straight on. Balance the telescope in both axes with the longer clutch levers.

Power up, choose an alignment (2-Star, 1-Star, Quick, Solar System or Last Alignment), and then run All-Star Polar Alignment from the hand control: the mount points to a bright star and walks you through adjusting the altitude and azimuth knobs. For imaging, train the permanent periodic error correction once and the mount keeps it after power-off.

The hand control has a USB port for a computer, and Celestron's free CPWI software adds advanced pointing models and an ASCOM interface for third-party capture programs.

Using the CGEM II in Colorado

• Latitude: its 15°–70° range covers all of Colorado (about 37° to 41° north) with lots of room to spare.
• Weight: the head is the heaviest piece at 40 lb. Many owners leave the tripod set up on a patio or in a backyard observatory and carry only the head in and out.
• Power at a dark site: the included DC power cable plugs into a car or a 12V power tank. At home, use the 5 amp AC adapter.

What to add for the best results

• A telescope (required): the EdgeHD 800 and EdgeHD 925 optical tubes for imaging, or the C9.25 and C11 SCTs for visual and planetary work.
• Celestron 5 amp AC adapter: runs the mount from a wall outlet. Celestron built it for the CGEM series.
• StarSense Autoguider: aligns the mount on its own in about three minutes, helps with polar alignment, and autoguides without a separate guide camera or laptop. It plugs into the AUX port, not the autoguider port.
• SkyPortal WiFi module: control the mount from your phone or tablet with the SkyPortal app.
• CGEM 11 lb counterweight: extra weight to balance a heavy imaging setup.
• CGE or CG-5 universal mounting plate: for mounting a telescope that doesn't have a dovetail.

Prefer a complete telescope? See the CGEM II 800 EdgeHD, CGEM II 925 EdgeHD and CGEM II 925 SCT.

Advanced VX vs. CGEM II vs. CGX

See all CGEM II telescopes and mounts.

What's in the box

• CGEM II equatorial mount head
• 2" steel tripod
• Accessory tray
• 17 lb counterweight
• NexStar+ hand control and hand control holster
• DC power cable (plugs into a car's 12V socket or a power tank)

The telescope, AC adapter and 12V battery are sold separately.

Celestron CGEM II FAQ

Is the CGEM II good for beginners?

Yes, if you're ready for its size. The hand control guides you through alignment and polar alignment step by step, and the mount is forgiving with heavier telescopes. If you want something lighter to carry, the Advanced VX is easier to move around.

What telescopes can the CGEM II carry?

Up to 40 lb of telescope and accessories. Celestron pairs it with its 8", 9.25" and 11" SCTs and EdgeHDs, the 8" RASA and the 7" Maksutov. For long-exposure imaging we suggest leaving some margin, so an 8" or 9.25" EdgeHD with a camera and guider is the sweet spot.

CGEM II or Advanced VX?

Choose the Advanced VX for a refractor or an SCT up to 8" and a mount that's easy to carry. Choose the CGEM II for 9.25" and 11" SCTs, or when an 8" imaging setup with all its accessories starts to push the Advanced VX's 30 lb limit.

What power does it need?

12V DC at 3.2A. The included cable runs it from a car or a 12V power tank, and the 5 amp AC adapter runs it from a wall outlet.

Can I use it for astrophotography?

Yes. It has an autoguider port, permanent PEC and internal cabling, and it can track past the meridian. Add the StarSense Autoguider, or a guide scope and guide camera, for guided exposures.

Can I see one before I buy?

Yes. The CGEM II is on display in our Denver store. Stop by and we'll show you how it sets up and how it handles an SCT.

Specifications