User manual CELESTRON NEXSTAR GPS

[. . . ] The NexStar GPS ushers in the next generation of computer automated telescopes. The NexStar GPS series, for the first time ever in a commercial telescope, uses GPS (Global Positioning System) technology to take the guesswork and effort out of aligning and finding celestial objects in the sky. Simple and easy to use, the NexStar with its on-board GPS, is up and running after locating just two alignment stars. It's so advanced that once you turn it on, the integrated GPS and digital compass system automatically pinpoints your exact location and points to your first alignment star. [. . . ] The position of the Big Dipper changes during the year and throughout the course of the night (see Figure 6-5). When the Big Dipper is low in the sky (i. e. , near the horizon), it may be difficult to locate. Observers in the southern hemisphere are not as fortunate as those in the northern hemisphere. The stars around the south celestial pole are not nearly as bright as those around the north. This star is just within naked eye limit (magnitude 5. 5) and lies about 59 arc minutes from the pole. Definition The north celestial pole is the point in the northern hemisphere around which all stars appear to rotate. The counterpart in the southern hemisphere is referred to as the south celestial pole. Figure 6-6 The two stars in the front of the bowl of the Big Dipper point to Polaris which is less than one degree from the true (north) celestial pole. Cassiopeia, the "W" shaped constellation, is on the opposite side of the pole from the Big Dipper. The North Celestial Pole (N. C. P. ) is marked by the "+" sign. Declination Drift Method of Polar Alignment This method of polar alignment allows you to get the most accurate alignment on the celestial pole and is required if you want to do long exposure deep-sky astrophotography through the telescope. The declination drift method requires that you monitor the drift of selected stars. The drift of each star tells you how far away the polar axis is pointing from the true celestial pole and in what direction. Although declination drift is simple and straight-forward, it requires a great deal of time and patience to complete when first attempted. The declination drift method should be done after any one of the previously mentioned methods has been completed. To perform the declination drift method you need to choose two bright stars. One should be near the eastern horizon and one due south near the meridian. Both stars should be near the celestial equator (i. e. , 0° declination). You will monitor the drift of each star one at a time and in declination only. While monitoring a star on the meridian, any misalignment in the east-west direction is revealed. While monitoring a star near the east/west horizon, any misalignment in the north-south direction is revealed. It is helpful to have an illuminated reticle eyepiece to help you recognize any drift. For very close alignment, a Barlow lens is also recommended since it increases the magnification and reveals any drift faster. When looking due south, insert the diagonal so the eyepiece points straight up. Insert the cross hair eyepiece and align the cross hairs so that one is parallel to the declination axis and the other is parallel to the right ascension axis. [. . . ] As a condition to the obligation of Celestron to repair or replace such product, the product must be returned to Celestron together with proof-of-purchase satisfactory to Celestron. The Proper Return Authorization Number must be obtained from Celestron in advance of return. Call Celestron at (310) 3289560 to receive the number to be displayed on the outside of your shipping container. All returns must be accompanied by a written statement setting forth the name, address, and daytime telephone number of the owner, together with a brief description of any claimed defects. [. . . ]