Celestron CGEM II 800 Schmidt-Cassegrain Telescopes CGEM II EQ Mount Manual 5l - Page 26

Updating your Star Alignment After polar alignment, it is a good idea to check the pointing accuracy of the telescope to see how much it may have been affected by moving the mount. Since the polar alignment process requires you to "sync" the telescope on a bright star before you begin, it will be necessary to undo the sync before re-aligning. To undo the sync: • Press the Align button and use the Up/Down buttons on the hand controller to select Undo Sync from the list, and press Enter. The message Complete will display on the LCD. To re-align your telescope: 1. Slew the telescope to one of the original alignment stars or another bright star if the original alignment stars are no longer in a convenient location. Press the Align button and use the Up/Down buttons on the hand controller to select Alignment Stars from the list. 2. The hand control will ask you which of the original alignment stars you wish to replace. Use the Up/Down buttons to select the desired star and press Enter. 3. Once again, center the star in the finderscope and press Enter. 4. C enter the star in the eyepiece and Press Align. 5. R epeat the process on a second alignment star. For additional all-sky pointing accuracy, it is a good idea to align on at least one additional calibration star located on the opposite side of the Meridian. To add calibration stars: 1. Slew the telescope to a bright star on the opposite side of the Meridian from your two alignment stars. 2. Press the Align button and use the Up/Down buttons on the hand controller to select Calib. Stars from the list, and press Enter. 3. A lign the star in the finderscope and then in the eyepiece as you did with the alignment stars. alignment, it does get you within one degree and is suitable for visual observing and short exposure piggyback photography. This must be done in the dark when Polaris is visible and can be done using the hole in the polar axis or with the help of the optional polar axis finderscope. 1. Set up the telescope so the polar axis is pointing towards north. 2. Remove the polar finderscope cover and the polar axis cover from both sides of the mount. The polar finderscope cover unthreads from the rear of the mount, and the polar axis cover presses into the front of the mount 3. Loosen the DEC clutch knob and move the telescope so the tube is perpendicular to the polar axis (i.e., the tube should be pointing either due west or east). 4. Look through the hole located underneath the polar finderscope cover (or through the eyepiece if using the optional polar axis finderscope). You should be able to see the sky from the hole under the polar axis cover. 5. Adjust the mount in altitude and/or azimuth until Polaris is visible through the polar axis hole. Center Polaris as accurately as possible. Like the Display Align method, this gets you close to the pole but not directly on it. For help in identifying and locating Polaris, read the section below. Finding the North Celestial Pole In each hemisphere, there is a point in the sky around which all the other stars appear to rotate. These points are called the celestial poles and are named for the hemisphere in which they reside. For example, in the northern hemisphere all stars move around the north celestial pole. When the telescope's polar axis is pointed at the celestial pole, it is parallel to the Earth's rotational axis. Big Dipper LiƩle Dipper Display Align - the user can now display the polar alignment error in the RA and DEC axes. These values show how close the mount is pointed at the celestial pole base on how accurately the user centered the alignment star with the hand control and with the mount adjustment. To display the alignment error: N.C.P Pointer Stars Polaris (North Star) Cassiopeia • Press the Align button and use the Up/Down buttons on the hand controller to select Display Align from the list, and press Enter. Pointing at Polaris This method of Polar aligning utilizes Polaris as a guidepost to the celestial pole. Since Polaris is less than a degree from the celestial pole, you can simply point the polar axis of your telescope at Polaris. Although this is by no means perfect Many methods of polar alignment require that you know how to find the celestial pole by identifying stars in the area. For those in the northern hemisphere, finding the celestial pole is not too difficult. Fortunately, we have a naked eye star less than a degree away. This star, Polaris, is the end star in the handle of the Little Dipper. Since the Little Dipper (technically called Ursa Minor) is not one of the brightest constellations 26 | ENGLISH