User manual CELESTRON G-3 Instruction Manual

[. . . ] G-3 and G-5 Telescope Models #11090 / #11091 / #11050/ #11051 CG-3 Equatorial Mount Model #91503-A INSTRUCTION MANUAL Focuser Ring Finderscope Finder Bracket Eyepiece Star Diagonal ¼"x20 Photo Adapter Mounting Platform Mounting Block Photo Adapter Tightening Knob Fig 1 ­ G-3 Optical tube Corrector Plate Optical Tube Finderscope Finder Bracket Mounting Block (G-5 Only) ¼" x 20 Photo Adapter Mounting Platform (Used for the G-3) Declination Setting Circle R. A. Slow Motion Knob Counterweight Counterweight Locking Screw Eyepiece Star Diagonal Declination Locking Knob Declination Slow Motion Knob Right Ascension Setting Circle Latitude Adjustment Knob R. A. Spur Gear Figure 2 ­ The G-5 Telescope Azimuth Adjustment Knob Counterweight Shaft Counterweight Shaft Safety Screw Tripod Leg 2 INTRODUCTION Congratulations on your purchase and welcome to the Celestron world of astronomy. If you're a newcomer to the hobby of astronomy, some of the terms and telescope components described in this instruction manual may be new to you. [. . . ] For example, in the northern hemisphere all stars appear to move around the north celestial pole (see figure 8). When the telescope's polar axis is pointed at the celestial pole, it is parallel to the Earth's rotational axis. 10 Many of the 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 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 in the sky, it may be difficult to locate, especially from urban areas. If this is the case, use the two end stars in the bowl of the Big Dipper. Draw an imaginary line through them toward the Little Dipper. The position of the Big Dipper will change during the year and throughout the course of the night. When the Big Dipper is low in the sky (i. e. , near the horizon) it may be difficult to locate. Figure 8 Figure 9 To make finding and tracking the stars easier, a rough polar alignment is required. The right ascension (polar) axis should be pointed towards the North Pole (see figure 9). Set the latitude of the telescope to the latitude of your observing location by turning the azimuth adjustment screws on the mount. The latitude of your observing location corresponds to the altitude that Polaris will appear to be above the horizon. For example, If you are observing from Los Angeles, which has a latitude of 34°, then the celestial pole (and Polaris) will be 34° above the 11 northern horizon. All a latitude scale does then is to point the polar axis of the telescope at the right elevation above the northern (or southern) horizon. Release the DEC lock knob and move the telescope so that the tube is parallel to the polar axis. When this is done, the declination setting circle will read +90°. If the declination setting circle is not aligned, move the telescope so that the tube is parallel to the polar axis. In the case of the G-3 telescope, loosen the knob under the mounting plate (see figure 1) and slowly move the tube sideto-side on the mounting plate until Polaris is seen in the finderscope. Then secure the tube to the mounting plate by tightening the knob. Using the altitude and azimuth adjustment screws, move the mount until Polaris is in the field of view of the finderscope. Rough adjustments in azimuth can be made by moving the tripod. [. . . ] The Proper Return Authorization Number must be obtained from CI in advance of return. Call Celestron at (310) 328-9560 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. Parts or product for which replacement is made shall become the property of CI. [. . . ]