ascensionRight axis
Declination setting circle
Declination lock lever
Front opening in R.A. 
axis
Latitude scale
Latitude adjustment
Azimuth fine adjustment knobs Declinationaxis
Figure 5: The equatorial mount of the AstroView 6
the focuser. Then carefully lift the eyepiece out of the holder. Do not tug or pull the eyepiece to the side, as this will knock the telescope off its target. Replace the eyepiece with the new one by sliding it gently into the holder.
4.Setting Up and Using the Equatorial Mount
When you look at the night sky, you no doubt have noticed that the stars appear to move slowly from east to west over time. That apparent motion is caused by the Earth’s rotation (from west to east). An equatorial mount (Figure 5) is designed to compensate for that motion, allowing you to easily “track” the movement of astronomical objects, thereby keeping them from drifting out of the telescope’s field of view while you’re observing.
This is accomplished by slowly rotating the telescope on its right ascension (R.A.) axis, using only the R.A.
Polar Alignment
For Northern Hemisphere observers, approximate polar alignment is achieved by pointing the mount’s R.A. axis at the North Star, or Polaris. It lies within 1° of the north celestial pole (NCP), which is an extension of the Earth’s rotational axis out into space. Stars in the Northern Hemisphere appear to revolve around Polaris.
To find Polaris in the sky, look north and locate the pattern of the Big Dipper (Figure 6). The two stars at the end of the
Right Ascension lock lever
Right Ascension setting circle lock thumb screw
Right Ascension setting circle
Polar axis finder scope
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Big Dipper | N.C.P. | |||
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Pointer |
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Stars |
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Figure 6. To find Polaris in the night sky, look north and find the Big Dipper. Extend an imaginary line from the two "Pointer Stars" in the bowl of the Big Dipper. Go about five times the distance between those stars and you'll reach Polaris, which lies within 1° of the north celestial pole (NCP).
“bowl” of the Big Dipper point right to Polaris. Observers in the Southern Hemisphere aren’t so fortunate to have a bright star so near the south celestial pole (SCP). The star Sigma Octantis lies about 1° from the SCP, but it is barely visible with the naked eye (magnitude 5.5).
For general visual observation, an approximate polar align- ment is sufficient:
1.Level the equatorial mount by adjusting the length of the three tripod legs.
2.Loosen one of the latitude adjusting
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