Celestron NexStar 11, Instruction Manual

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Latitude Scale Polar Alignment Method
The easiest way to polar align a telescope is with a latitude scale. Unlike other methods that require you to find the
celestial pole by identifying certain stars near it, this method works off of a known constant, latitude, to determine how
high the polar axis should be pointed.
If you know the latitude of your observing site then you can determine the altitude the tilt plate needs to be set at.
There is a relationship between your latitude and the angular distance (altitude) the celestial pole is above the northern
(or southern) horizon. The angular distance from the northern horizon to the north celestial pole is always equal to
your latitude. In other words, the altitude you need to set your tilt plate at is the same as the latitude of your observing
site.
If you are observing from Los Angeles, which has a latitude of 34°, then the celestial pole would be 34° above the
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. To align your telescope:
1. Use the EQ North alignment method (discussed above) to position the optical tube parallel with the fork arms.
2. Adjust the equatorial wedge in altitude until the latitude indicator points to your latitude.
This method can be done in daylight, thus eliminating the need to fumble around in the dark. Although this method
does NOT put you directly on the pole, it will limit the number of corrections needed when tracking an object. It will
also be accurate enough for short exposure prime focus planetary photography (a couple of seconds) and short exposure
piggyback astrophotography.
Pointing at Polaris Method of Polar Alignment
This method uses Polaris as a guidepost to the celestial pole. Since Polaris is less than a degree from the celestial pole,
you can simply point the polar axis of your telescope at Polaris. Although this is by no means perfect alignment, it
does get you within one degree. Unlike the previous method, this must be done in the dark when Polaris is visible.
1. Use the EQ North alignment method (discussed above) to position the optical tube parallel with the fork arms.
2. Adjust the wedge in altitude and/or azimuth until Polaris is in the field of view of the finder.
3. Center Polaris in the field of the telescope using the altitude and azimuth adjustment on the wedge.
Figure 6-6
The two stars in the front of the bowl of the Big Dipper point to Polaris which is less than
one degree from the true (north) celestial pole. Cassiopeia, the “W” shaped constellation,
is on the opposite side of the pole from the Big Dipper. The North Celestial Pole (N.C.P.)
is marked by the “+” sign.