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10″ Celestron StarSense Explorer Dobsonian Review

An 8” or 10” Dobsonian reflector has long been considered an ideal starting telescope. They are cheap, simple, and will last the observer a long time, possibly forever. While there have been attempts through the years to bring these inexpensive Dobs into the electronic age, none have really stuck. Time will tell, but this may change with Celestron’s new StarSense line, which uses your smartphone as an all-in-one navigation aid and information center.

The Celestron StarSense Dobsonian will be familiar to users of other solid-tubed Dobsonians. Credit: Ed Ting

The telescope arrived in two cartons. One contained the optical tube assembly, while the rocker box was flat packed in the other. All the required tools are included, and it took me about 40 minutes at an unhurried pace to assemble the scope. Other than the StarSense dock, the telescope will look familiar to anyone who has used solid-tubed Dobsonians. The scope has a 10” f/4.7 mirror with a focal length of 1250mm. The optical tube weighs 30 lbs, while the rocker box weighs 24 lbs. These numbers are in line with conventional 10” Dobsonians.

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This is not a “goto” telescope. There are no motors; the user pushes the scope manually, using a smartphone as a navigation aid. Also, use of the StarSense is not required. Leave your phone in your pocket and just move the scope around the sky, if desired. I did just that for the first few nights while I got acquainted with the scope.

When you’re ready to use the StarSense, download the app. Celestron advises you to wait until you’re on wi-fi, as it’s a 464 mb download. The paperwork included with the scope contains one download code for their version of Starry Night Pro, and five codes for the StarSense. There are no instructions for the app, but I found none were necessary. Remove the duckbill-shaped cover on the dock, install your phone, start up the app and it will walk you through the process.

The duckbill-shaped curved piece on the StarSense dock is a dust cover that exposes a 45-degree angled mirror. Credit: Ed Ting

There are two important steps to get right the first time you use the app. First, with the phone docked in the cradle, maneuver the X and Y axis knobs until your phone’s camera is centered in the angled mirror. You’ll know when you get it right. Second, while sighting a distant object (the top of a tree or telephone pole, a mailbox, etc) in the eyepiece, drag the red crosshairs on the app until it’s centered. You can pinch and/or zoom if necessary for accuracy. The app calculates the offset internally. There is no need to repeat this step. Each time you turn on the app, it remembers the offset. It may take you a few tries to get this second step right. If you find the scope’s pointing accuracy is slightly off, this is likely the culprit.

The author’s iPhone 11 in the StarSense dock, ready for action. Credit: Ed Ting

That’s it. Once you’re out at night, the StarSense becomes your personal assistant to the night sky. There is no need to point the scope at two bright objects as in many conventional operating systems. The app uses your phone’s camera to take images of the night sky, comparing them to an internal database, and knows its location as a result.

The app starts off by suggesting the brighter showpiece objects, and when you select one, an arrow shows up on your phone’s screen, telling you where to push the scope. As you get closer, the view zooms in so you can fine tune your movements. When you’re on the target, the round target box changes to a square one. One caution – go slow. Watch your phone; the app will periodically tell you to stop moving while it re-acquires its position in the sky.

The StarSense app starts off showing suggested objects in tonight’s sky. Note that the app shows which objects are visible from the city. Credit: Ed Ting

 

The app shows you the direction to move the scope to your target (in this case, globular cluster M13). Note the yellow circle. Credit: Ed Ting

 

Once on the target, the yellow circle changes to a green square. (Note: In Night Mode, everything is red, but the circle still changes to a square). Credit: Ed Ting

Once on the target, check the eyepiece; the object should be there. I found the StarSense’s accuracy to be quite good. It placed objects in the field of view of the supplied 25mm eyepiece (48X). The app contains a library of information with astrophotographs, as well as audio narration for those inclined to listen. Over the course of several nights, the app directed me to M13, M92, M13, M15, M52, M103, Saturn, Jupiter, M33, and many more objects. The app helped me when I could not quite remember the locations of M10, M12, NGC 7331, and NGC 7662.

I had a few minor complaints. The optical tube’s back-heavy bias required me to tighten the altitude knobs almost all the way. This resulted in motions that were on the stiff side of neutral (as a counterpoint, I’ll point out some observers actually prefer stiffer motions). If you don’t use the StarSense, the position of the red dot reflex sight mounted on the opposite side of the optical tube will make you crane your neck a little. The app did crash on me a couple of times; restarting it always cured the problem. I used an iPhone 11. Different phones may have differing levels of accuracy. Finally, I found the StarSense’s cradle moved a little too easily when inserting or removing the phone, disturbing the careful alignment. Over time, I learned which pieces I could touch in the dock.

The 10” StarSense Dob’s biggest competitor may come from its smaller 8” brother. At $799 vs $1099, the 8” version makes a compelling case as a sweet spot for light gathering ability, portability, and price. You won’t go wrong with either. The choice is yours!

 

MSRP: $1,099
Website: 
Celestron.com

 

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About Ed Ting

Ed Ting is a well-known amateur astronomer. His work has appeared in Sky & Telescope, Night Sky, Skywatch, Amateur Astronomy, Discover, and Popular Mechanics magazines. His web site, www.scopereviews.com, is a widely-read telescope review web site. He is a National Science Foundation Ambassador to Chile and a NASA Solar System Ambassador.

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