One of the most
daunting things about
astronomy is that there are so many darn things out there in the sky to look at. The chore of locating and identifying items of interest in the heavens
intimidate many who would otherwise be attracted to stargazing. Self-pointing telescopes provide an easy solution to this problem.
Many budding astronomers buy a very nice telescope, and wind up spending their time with planetary astronomy, as the planets are relatively easy to find. Just by pointing the ‘scope at the brightest items in the sky, one can find objects such as Jupiter, Venus, or Saturn. However, that same 4-in. reflector you use to see Jupiter’s moons can also show you nebulae and stars like the bluish Vega and orange Arcturus.
Once one gets past the obvious targets of interest, finding specific items of interest can be a chore, even for those knowledgeable enough to use a planisphere or ephemeris. This often results in telescopes winding up an interesting conversation piece in the living room corner, hauled out onto the balcony once in a while to impress guests, or worse still, end up gathering dust in the garage or basement next to the exercise equipment.
The self-guiding telescope.
Professional telescopes in observatories use computers and servomotors to steer themselves, pointing automatically in the desired direction, using an internal database, or coordinates given to it by the astronomer. Once locked on, they also track the object of interest as it moves across the sky (caused by the Earth rotating beneath it), allowing the astronomer to observe or take photographs with long exposure times through the telescope without blurring.
That capability is now available to the amateur astronomer, powered by the increasing power of personal electronics. The same technology that allows you to put a computer in your pocket now allows you to buy a computer-steered telescope with capabilities that can rival that of a professional facility. These “Go-To” telescopes have the motors, logic, memory, and software to locate and point to just about every object in the heavens.
Professional telescopes in observatories use computers and servomotors to steer themselves, pointing automatically in the desired direction, using an internal database, or coordinates given to it by the astronomer. Once locked on, they also track the object of interest as it moves across the sky (caused by the Earth rotating beneath it), allowing the astronomer to observe or take photographs with long exposure times through the telescope without blurring.
That capability is now available to the amateur astronomer, powered by the increasing power of personal electronics. The same technology that allows you to put a computer in your pocket now allows you to buy a computer-steered telescope with capabilities that can rival that of a professional facility. These “Go-To” telescopes have the motors, logic, memory, and software to locate and point to just about every object in the heavens.
A self-pointing telescope operates by determining its location very precisely, so that it can center its three-dimensional map of the heavens upon itself. It starts by ensuring that it is properly set up with a level base oriented in the proper relationship to north. Once the base is set up properly, the ‘scope then points at a few alignment stars so that the user can verify that the 'scope “knows” where it is.
Once the ‘scope has been set up, it can show you any of the stars in its memory. Even the least of the self-pointing telescopes has a memory of thousands of celestial objects. Some have features that show you interesting objects in the sky based upon season, or magnitude, or your location. Some even will filter out low-brightness objects to compensate for city viewing or poor conditions.
Another great feature of these devices is their ability to track an object, keeping it in its field of view as long necessary, enabling long-term observation of phenomena or astronomical photography using long exposure times.
The most important aspect of a self-pointing telescope is proper set-up and alignment. If the ‘scope isn’t locked-in to its internal map, it can’t point at anything, as its knowledge of where it is doesn’t correspond with the world outside.
For some, the set-up of a self-pointing telescope is as daunting as operating a standard ‘scope. For these users, and for those who simply want as easy a set-up as possible, there are now GPS-enabled telescopes that do just about everything for the user. These ‘scopes integrate Global Positioning System satellite information with internal position sensors to align themselves. They still need some external input from the user, but that is usually limited to verifying that the telescope points at its first alignment star. There is no need to enter the date, time, location, or even the position of north.