User manual ORION TELESCOPES & BINOCULARS REVC 9026 ASTROVW 120

[. . . ] INSTRUCTION MANUAL Orion AstroView 120 EQ ® TM #9026 Equatorial Refracting Telescope Customer Support (800) 676-1343 E-mail: support@telescope. com Corporate Offices (831) 763-7000 Providing Exceptional Consumer Optical Products Since 1975 P. O. Box 1815, Santa Cruz, CA 95061 IN 124 Rev. C 0900 Tube rings Objective lens cell Dew cap/ lens shade Right Ascension slow-motion control (not visible) Declination lock lever Latitude adjustment T-bolts Counterweight shaft Small counterweight Large counterweight Finder scope Finder bracket Eyepiece Star diagonal Focus knob Declination slow-motion control Right Ascension lock lever Polar axis finder scope Counterweight lock thumbscrews "Toe saver" retaining bolt Azimuth fine adjustment knobs Tripod leg Accessory tray bracket attachment point Accessory tray bracket Accessory tray Leg lock knob Figure 1. The AstroView 120 EQ Refractor 2 Congratulations on your purchase of a quality Orion telescope! [. . . ] So, the coordinates for the Orion Nebula listed in a star atlas will look like this: R. A. -5° 27' That's 5 hours and 35. 4 minutes in right ascension, and -5 degrees and 27 arc-minutes in declination (the negative sign denotes south of the celestial equator). There are 60 minutes in 1 hour of R. A and there are 60 arc-minutes in 1 degree of declination. setting circle is scaled in hours, from 1 through 24, with small lines in between representing 10minute increments. The upper set of numbers apply to viewing in the Northern Hemisphere, while the numbers below them apply to viewing in the Southern Hemisphere. Before you can use the setting circles to locate objects, the mount must be accurately polar aligned, and the setting circles must be calibrated. The declination setting circle was calibrated at the factory, and should read 90° when the telescope optical tube is pointing exactly along the polar axis. Calibrating the Right Ascension Setting Circle 1. Identify a bright star near the celestial equator and look up its coordinates in a star atlas. lock levers on the equatorial mount, so the telescope optical tube can move freely. 3 Point the telescope at the bright star whose coordinates you know. Center the star in the telescope's eyepiece. Loosen the large setscrew just above the R. A. setting circle so the pointer indicates the R. A. coordinate listed for the bright star in the star atlas. Do not retighten the setscrew when using the R. A. setting circles for finding objects; the set screw is only needed for polar alignment using the polar axis finder scope. Finding Objects With the Setting Circles Now that both setting circles are calibrated, look up in a star atlas the coordinates of an object you wish to view. lock knob and rotate the telescope until the Dec. value from the star atlas matches the reading on the Dec. Note: If the telescope is being aimed toward the south and the Dec. setting circle pointer passes the 0° indicator, the value on the Dec. [. . . ] Terrestrial Viewing The AstroView 120 Refractor may also be used for long-distance viewing over land. For this application we recommend substitution of an Orion 45° Correct-Image Diagonal (#8790) for the 90° star diagonal that comes standard with the telescope. The correctimage diagonal will yield an upright, nonreversed image and also provides a more comfortable viewing angle, since the telescope will be aimed more horizontally for terrestrial subjects. For terrestrial viewing, it's best to stick with low powers of 50x or less. [. . . ]