User manual CELESTRON C11

[. . . ] 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. This manual is designed to instruct you in the proper use of your Celestron C80HD Refractor, C102-HD Refractor, C11 4. 5 Newtonian or C150-HD Newtonian as well as the CG-4 Equatorial Mount. To assist you in assembling and operating your telescope, take time to review this manual and the parts diagram listed in Figure 1. WARNING--NEVER LOOK AT THE SUN WITH YOUR TELESCOPE OR ITS FINDERSCOPE. PERMANENT AND IRREVERSIBLE EYE DAMAGE MAY RESULT AS WELL AS DAMAGE TO YOUR TELESCOPE. [. . . ] To calculate the magnification we use the following formula: Magnification = FL(telescope) FL(eyepiece) where FL(telescope) is the focal length of the telescope and FL(eyepiece) is the focal length of the eyepiece. For example, if the focal length of the telescope is 910mm and you use a 20mm eyepiece your magnification is 910/20 = 46x. There are numerous optional eyepieces that are available to expand your range of magnification. There are various types of eyepieces of varying quality to choose from. The Celestial - Coordinate System. The celestial-coordinate system is an imaginary projection of the Earth's geographical coordinate system onto the celestial sphere which seems to turn overhead at night. This celestial grid is complete with equator, latitudes, longitudes and poles. Actually the celestial-coordinate system is being displaced very slowly with respect to the stars. This is called precession and is caused by gravitational influences from the Sun, Moon and other celestial bodies. The celestial equator is a full 360º circle bisecting the celestial sphere into the northern celestial hemisphere and the southern celestial hemisphere. Like the Earth's equator, it is the prime parallel of latitude and is designated 0º. The celestial parallels of latitude are called "coordinates of declination (Dec. )", and like the Earth's latitudes they are named for their angular distances from the equator. There are 60 minutes of arc in each degree, and 60 seconds of arc in each arc minute. Declinations north of the celestial equator are "+" and declinations south are "-". The declination setting circle is aligned during the process of polar alignment. setting circle, you will need to know the names of a few of the brightest stars in the sky. If you don't, they can be learned by using the Celestron Sky Maps (#93722) or consulting a current astronomy magazine. The farther you are from the celestial pole the better your reading on the R. A. The star you choose to align the setting circle with should be a bright one whose coordinates are known and easy to look up. If you purchased an optional motor drive, start it now so that it will track the star. setting circle does NOT move as the telescope moves in R. A. , the setting circle must be aligned each time you want to use it to find an object. Instead, you can use the coordinates of the object you are currently observing. 2. 6. Once the setting circles are aligned you can use them to find any objects with known coordinates. The accuracy of your setting circles is directly related to the accuracy of your polar alignment. 1. Use a seasonal star chart to make sure the object you chose is above the horizon. [. . . ] Collimation Tool for Newtonians (#94183) - A helpful aid to collimating your telescope. Polar Axis Finderscope (#94221) ­ This useful accessory helps speeds accurate polar alignment by using an etched reticle for finding the North Celestial Pole. It requires a 35mm SLR camera and a T-Ring for your brand of camera. Other - Numerous other accessories are available. See the Celestron Accessory Catalog (#93685) or ask your Celestron dealer for details. 16 CELESTRON TWO YEAR WARRANTY A. [. . . ]