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To do this, you use your RA and DEC setting circles to find celestial coordinates for stellar objects. These coordinates are given in star charts and reference books. Polar Alignment To make tracking the stars easier, rough polar alignment is required. 1. The right ascension (polar) axis should be pointed towards the North Pole (see the illustration below). 2. The equatorial mount should be level. 3. Your latitude should be set (see section on “Setting Latitude” on page 7). 10 See the illustration below if you are not sure where the North Pole is located Figure 3A For the most part, to find astronomical objects you’ll be using the right ascension axis, as polar alignment virtually eliminates the need to adjust the declination axis. To track objects continuously, adjustments must be made with the right ascension cable, otherwise the rotation of the earth will cause the object you’re viewing to drift out of your field of view. The method of polar alignment described above is adequate for casual observing. More precise methods of polar alignment are available, and most astronomy or telescope textbooks describe these procedures. Look at the North Star after doing the polar alignment procedure given here - your declination setting circle should read 90“. SETTING CIRCLES The setting circles are dials, or gauges, for right ascension and declination that allow you to locate a celestial object easily using its coordinates, as listed in a star chart or atlas. The declination setting circle is scaled in degrees and the right ascension setting circle is laid out in increments of minutes. The setting circles will assist you to get close to your target, but not directly on it. It’s important to note that he accuracy of your polar alignment will affect the accuracy of your setting circles readings. The declination setting circle is set at the factory and won't require adjustment if it reads accurately. The right ascension setting circle must be aligned. Choose a bright and easy to find star on a star chart, and note its right 11 ascension and declination coordinates. Find the star and center it first in the fmderscope, then in the telescope. Rotate the right ascension circle to match the coordinates of the star with the indicator mark. The right ascension setting circle does not move as the telescope moves in right ascension, and thus it must be aligned each time you want to use it to find a new object. However, you don’t need to use a bright star each time. Instead, you can use the object you’re observing at the time. Now, using a star chart or atlas, you can find numerous,objects. First, move the telescope in declination to the correct declination coordinate. Then move the telescope in right ascension until the indicator points to the correct coordinate. After moving the telescope to the correct celestial coordinates, look through the fmderscope to see if you have located the object you wish to view. Center the object in the fmderscope. Now look through the telescope with a low power eyepiece, and the object should be in view. Fainter objects may not be visible in the fmderscope. If this is the case, gradually pan the telescope, using the right ascension and declination cables, until the object is visible. MAGNIFICATION The magnification (or power) of a telescope varies depending upon the focal length of the eyepiece being used and the focal length of the telescope. The Firstscope 60 telescope has a focal length of 900mm and the Firstscope 60 EQ Deluxe comes with a 25mm 1 'A" eyepiece. To calculate magnification, use the following formula, in which FL = focal length: FL (telescope) in mm Magnification = CJ , . , . * J rL (eyepiece) in mm Therefore, if you use the 25mm eyepiece your magnification is 900/25 = 36x. The same formula can be applied to any of your eyepieces. Celestron offers numerous optional eyepieces to expand your range of magnification. Eyepieces come in barrel diameters of .96" and \'A". In general, I'A" eyepieces are of a higher optical quality and give you sharper images, along with a wider field of view and better eye relief. Magnification through the telescope has its limits. These limits are determined by the laws of optics and the nature of the human eye. The maximum usable power (with sharp images) is equal to 60 times the aperture of the telescope (in inches). So, with a 60mm telescope it has a maximum useful power of 142x (2.3622" x 60) and with the 70mm the maximum is 165x (2.7559 x 60). Most of your viewing will be done in the range of 30x to 120x. Higher powers are used mainly for lunar and sometimes planetary observing where you can greatly enlarge the image. The images at extremely high powers like 675x magnify the image bur remember that the contrast will be very low and the image somewhat blurred due to the super power. For the brightest images with the most contrast, use the lower powers with a smaller image scale. 12 TELESCOPE OPERATION — ASTRONOMICAL OBS...

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