The NexStar computer hand control has a built-in database of more than 40,000 stars, deep space objects, and solar system objects it can locate for you. The computer's memory contains the following objects:

• the entire RNGC (Revised New General Catalog) of 7840 nebulas, galaxies, and star clusters

• the IC (Index Catalog) of 5386 nebulas, galaxies, and star clusters

• the Messier Catalog of the 110 best known deep sky objects

• the Caldwell Catalog of 109 fascinating objects that Messier missed

• 20 famous asterisms

• the Abell Catalog of 2712 galaxy clusters

• 25 selected CCD imaging objects

• 29,500 selected SAO stars, including variable stars and multiple star systems.

Also included are the eight major planets out to Pluto, as well as the Moon, for a total database more than 40,000 stars and objects. It's enough fascinating objects to keep you busy observing for the rest of your life.

You can also store and edit the right ascension and declination of 100 objects of your own choosing, such as the comet and asteroid coordinates published monthly in Astronomy and Sky & Telescope magazines. The computer control can quickly find any of those objects at your command, and track them with high accuracy for visual observing or casual astrophotography.

A review in Sky & Telescope magazine commented, "To quantify the Go To pointing accuracy, I spent several nights slewing to 50 objects selected from the NexStar's database. About one-third of them ended up dead center in the field, another third landed within ½° of the center, and the remaining third were within 1° of the center."

All of the database and scope operation information is displayed on a double line, 16-character, liquid crystal display on the hand control. This display leads you through the steps necessary to line up the scope on the sky, locate objects, control scope functions like the brightness of the hand control display, and much more. It shows you basic information about the object being viewed (such as the object's name, catalog designation, type, magnitude, and so forth). In addition to this basic information, there is enhanced information on over 200 of the most note-worthy objects. The display also shows you the right ascension and declination coordinates at which the scope is currently aimed.

The Sky & Telescope review said, "After using several NexStar-equipped telescopes in recent years, I can attest to the quality of the software and hardware for Celestron's Go To system. The package is reliable and offers quick access to an excellent array of databases. I especially like Celestron's Tour mode, which steps a user through an eclectic choice of deep-sky objects, quirky asterisms, and fine double stars, the latter being a class of objects great for urban observing that many Go To systems ignore. Using NexStar scopes, I've been introduced to many fine double stars."

There are 19 fiber optic backlit LED buttons that glow a soft red in the dark to make it easy for you to control the computer without affecting your dark-adapted vision. An RS-232 communication port on the hand control allows you to operate the telescope via a personal computer using optional NexRemote telescope control software. The Sky & Telescope review said, "The author tried Windows and Mac programs, including Desktop Universe, ECU, MegaStar, SkyMap Pro, Starry Night, and TheSky, and all controlled the mount without any problems." You can upgrade the software via the internet from Celestron's website so you can always have the latest version of the NexStar software available to control your scope.

There is also an Autoguider port that can use a CCD autoguider to automatically control the drive motors during long exposure astrophotography. A high precision pointing subroutine ("precise go-to") in the computer lets you point accurately at objects that you want to photograph that are too dim to be seen though the scope.

Several different alignment methods are built into the NexStar computer, allowing you to choose a level of computer accuracy in automatically finding objects with which you are comfortable. Both the two star "quick align" procedure and two more accurate three star alignment methods (one computer-guided) are easily accomplished in only a few short minutes. You can be observing in less than 15 minutes after you first take the scope outdoors, including telescope set-up time.

In addition, the NexStar computer hand control is GPS-compatible (using an optional inexpensive SkySync GPS module) for full GPS (Global Positioning System) satellite accuracy. Adding GPS to the computer is something no competitive scope can do. Once the scope is approximately polar aligned, the 16-channel SkySync GPS system uses signals from government satellites to calculate the scope's location on earth in three dimensions with an accuracy measured in meters. The system also calculates the current time based on the split second accuracy of the GPS time signals.

After the SkySync quickly completes these calculations and enters the information into the computer control for you automatically, the computer then orients the scope with the sky, slews to a pair of guide stars, asks you to confirm that the stars are in the center of the field (and center them if they're not precisely aligned), and then starts finding and tracking over 40,000 objects for you at your command. With the Advanced Series go-to mount and the SkySync, orienting the scope in time and space on earth and aligning the scope on the sky becomes almost as easy a task as simply turning the scope on.