The Lake County Astronomical Society

Go-To?

Jack Kramer

Imagine yourself operating the giant Keck telescope on Mauna Kea. Would you star-hop to an elusive galaxy or plug the object into the computer and let the telescope find it? Seems pretty obvious that "Go-To" is the answer here. On a smaller scale, if you're at a public star party where guests are impatiently waiting to see the prominent absorption band in the Sombrero Galaxy, getting there is a lot faster if your scope is equipped with Go-To. The Sombrero is visible from all but the most light polluted locations, and if you're observing from your suburban back yard where nearby shopping center lights make guide stars all but invisible, then Go-To makes getting there a lot faster, as well.

I enjoy the leisurely hunt for objects and over the years have become pretty competent at finding my way around the night sky. So I have no personal need for a Go-To equipped telescope (or for digital setting circles). And many times while star hopping, we "discover" a totally unexpected object on the way to the original target. I also enjoy coming across as a stodgy old star hopper in order to elicit good-natured bantering with those who are sold on the Go-To technology.

Nonetheless, there are recognizable benefits to pushing a few buttons and letting the telescope slew over to a faint target. The price of Go-To is now to the point where it's easily within many observers' budgets and the technology itself is often an incentive for those of us who are techno-geeks. That's both good and bad. To paraphrase an old expression, when Go-To is good, it's very good; when it's bad, it's very bad. So if you've made up your mind that you want it, you're aware of the advantages. But there are some additional considerations.

Probably the biggest red flag is the inexpensive telescopes that feature Go-To - some are available starting at around $300. For that price you get a database containing around 1500 objects and a small telescope on a shaky mount that can see only a fraction of the deep sky objects in the system. To get Go-To into an Lake County Astronomical Society Night Times Page 7 inexpensive package, the manufacturer has put their effort into the technology and stinted on the quality of the optics and mounting. Moreover, there are many reports on various Internet astronomy forums that the motors on these telescopes are of such poor quality that the failure rate is quite high. Poorly executed high-tech systems have a high frustration quotient. Even the popular and generally reliable Meade ETX series has many parts made of plastic which wear out prematurely. Past experience has prompted Meade to re-fabricate some of these parts with metal on the newer models.

The other caveat is a mistaken belief among newcomers that Go-To will quickly teach them how to find their way around the sky. For those new to astronomy, the task of sorting out where things are located in the depths of space is daunting. There is a natural impatience to find stuff, and Go-To appears to be the answer. The thought is that all you have to do is identify a few key stars to align the system and off you go. But total reliance on the technology doesn't speed up the learning process; it actually hinders it. Quite a few Go-To users have an idea where the scope is pointed, but don't know the star field where the target lies and frequently are not even able to recognize the surrounding constellation. A correspondent on one of the Internet chat groups commented: "Just this past year I have had lots of experiences with people who play a good game but are not for real. One was folks who were asking where one particular major spring star was so they could start to line up their go-to mount. They had this beautiful group of equipment and 'seemed' to know what they were talking about at first. Well, it was November!"

A few years ago, I was observing with a friend who had equipped his scope with digital setting circles. He was having a problem with their alignment and after a couple of frustrating hours trying to get everything to work right, he gave up and went home. If you can't find deep sky objects unassisted, what happens when the equipment fails or (heaven forbid) the battery dies? You've become a slave to technology. A related problem arises with a few scopes that can be used only with the Go-To feature. Make sure that if the unit fails you can still use the telescope the old-fashioned way - by moving it manually.

Another item is the product life cycle. If something goes haywire with the drive system later on, will you be able to get it repaired? A dealer on one Internet discussion group lamented that with new models constantly replacing existing products, it has become difficult to get replacement parts for some telescopes just four or five years old. His concern was that Go-To systems, being essentially high-tech, are the first things to become obsolete, plus glitches are a common occurrence in earlier versions. A system that is upgradable offers some protection against obsolescence. Of course, the telescope itself won't be obsolete, so you could buy a new mounting for it if the old one bites the dust.

So my take on Go-To is this: first invest the time to learn your way around the sky a bit on your own; who knows, you may find pleasure in that pursuit on its own merits. (I always recommend that newcomers start out with a manageable Dobsonian-mounted Newtonian telescope.) When you do get a telescope equipped with Go-To, spend your money wisely on a good overall system - one that includes high quality optics, a solid mounting, and well designed and reliable computer interface.

Go-To is remarkable technology and in many cases it's useful, but it's not a panacea.