Amateur Astronomers Association of Princeton

by Gene Allen

In early 2020 Celestron introduced a line of low-end telescopes which include some very high-end technology. They did themselves and their customers a great disservice by re-using the StarSense label, because this new tech is orders of magnitude different from all earlier components bearing that name. I purchased and use a $300 StarSense accessory on my AVX mount. It is a camera that does a respectable job of automating a 3-star alignment. It picks up the data from the GPS accessory and, on a GEM, requires that a decent polar alignment has been otherwise accomplished. Similar tech seems to come included on some fork-mounted SCTs, but it is just that: automated multi-star alignment.

To distinguish the new technology one must use “StarSense Explorer,” and so far that only describes four below-entry-level, alt-az, push-to scopes. The genuine magic of the SSE tech is that it uses your fairly late model smartphone to actually plate solve a view of the night sky and present arrows to direct you to your chosen target. The cellphone clips into a bracket with a mirror that offers the phone camera a sufficient chunk of sky. Using a distant target in daylight, you tweak the center of the camera view to match the center of the eyepiece view, and you’re done. No pole star, no star alignment at all – ever. A free app runs the camera and does all the calcs internally, so no internet needed. It is reported to do a great job in all but the most heavily light-polluted skies. It can even be interrupted to answer a phone call without having a seizure. If the tripod is kicked or moved to get a target out of the trees, it re-solves in moments and happily continues. The catalog includes only Messier and Caldwell entries (and their NGC equivalents), but the two big disappointments are that the app needs an activation code to provide the pointing directions, and the code and phone dock are only offered with a telescope purchase. They are not (yet?) available as a separate accessory.

Having read through the 27 pages (as of this writing) of the leading SSE thread on CloudyNights after Dave Skitt brought it to my attention, my conclusion is that the only possible contender of the four is the 130mm reflector for $400. Most components are plastic and flimsy, stretching for bottom dollar. The 114mm reflector is of the discredited Bird-Jones design, and the two LT models ($180) have even less capable tripods and slo-mo control of only altitude. One respondent upgraded the focuser, diagonal, and eyepieces on the 102mm refractor, and then returned it because it still provided inadequate views when compared to his WO 102. Part of the issue is that for nearly the same money as the somewhat better DX models one can buy significantly better optics with conventional go-to automation and tracking.

As one might expect, the CN crew jumped right on it, cannibalizing scopes to jury rig the docks onto capable tubes of all types. My informal sense of the more than 600 entries is that the majority deal with just that. There are numerous appeals for Celestron to offer a semi-universal, maybe dovetail-mounting version of the dock plus the activation code as a separate accessory. Will Celestron do so, or offer it on better tubes? They will miss a tremendous opportunity if they persist in limiting SSE to dismal hardware. The good part is that now that they have shown what’s possible, others are likely to take up the cause. Open source plate solving algorithms are reportedly available, and some wizard will likely reverse engineer the app or come up with their own. Designs to 3D print a lighter weight (though less universal) dock are already underway.

So, returning to Dave’s original query, StarSense Explorer scopes offer unmatched technology on hardware that cannot be recommended with any confidence. Please do your own research and draw your own conclusions. Mine is that they offer exciting potential but are sadly not ready for even beginner prime time. Artemis says, “We go.” I say, “We wait.”