Specifications

Latitude Scales
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 to determine how high the polar axis should be pointed. The Losmandy G-11
mount can be adjusted from 14° to 64°.
The constant, mentioned above, is a relationship between your latitude and the angular distance
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. To illustrate this,
imagine that you are standing on the North Pole. latitude +90°. The North Celestial Pole. which
has a declination of +90
0
• would be directly overhead (90
0
above the horizon). Now. let's say that
you move 1° south. Your latitude is now +89° and the celestial pole is no longer directly
overhead. It has moved 1
0
closer toward the northern horizon. This means the pole is now 89
0
above the northern horizon. If you move 1 ° further south. the same thing happens again. As you
can see from this example, the distance from the northern horizon to the celestial pole is always
equal to your latitude.
If you are observing from San Diego, which has a latitude of 32°57', then the celestial pole is
32°57' 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 polar align your
telescope:
1. Make sure the polar axis of the mount is pointing due north. Use a landmark that you
know faces north.
2. Level the tripod. There is a bubble level built into the mount for this purpose. Please
note that leveling the tripod is only necessary if using this method of polar alignment.
Perfect polar alignment is still possible using other methods described later without
leveling the tripod.
3. Adjust the mount in altitude until the latitude indicator points to your latitude. Moving
the mount affects the angle the polar axis is pointing. For specific information on
adjusting the equatorial mount, please see the section Adjusting the Mount.
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
you will make 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 astro-
photography (a couple of minutes).
Pointing at Polaris
This method utilizes Polaris to polar align your mount. Since Polaris is less than 1
0
from the North
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 1°. Unlike the previous method, this must be
done in the dark when Polaris is visible.
1. Set the telescope up so that the polar axis is pointing north.
2. Loosen the DEC clutch knob and move the telescope so that the tube is parallel to
the polar axis. When this is done, the declination setting circle will read +90
0
• If the
declination setting circle is not aligned, move the telescope so that the tube is parallel
to the polar axis.
3. Adjust the mount in altitude and/or azimuth until Polaris is in the field of view of the
finder.
4. Center Polaris in the field of the telescope using the fine adjustment controls on the
wedge.
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