loosen the Dec. lock knob (12). The telescope should now be able to move freely on the Dec. axis. Loosen the ring clamps on the tube rings (10) a few turns, until you can slide the telescope tube forward and back inside the rings (this can be aided by using a slight twisting motion on the optical tube while you push or pull on it).
6.Position the telescope in the tube rings (10) so it remains horizontal when you carefully let go with both hands. This is the balance point for the optical tube (11) with respect to the Dec. axis.
7.Retighten the ring clamps.
3.5. Polar Alignment of the Equatorial mount
Objects located in the sky appear to revolve around the celestial pole. In northern latitudes, the North Star (Polaris) is close to the pole. (In actual fact, stars are essentially "fixed" in place and their apparent motion is caused by the earth rotating around its own axis.) Over a 24 hour period, stars will perform a complete revolution around the pole, generating concentric circles with the pole at their center. By aligning the telescope's polar axis with the celestial north pole (or with the celestial south pole for observers located in the earth's southern hemisphere), astronomic objects may be followed (or tracked) by simply moving the telescope around an axis, the polar axis.
If the telescope is reasonably aligned with the pole, changing the instrument's declination using its flexible control cable will consequently be of little use – almost all the telescope motion required will take place using the Right Ascension coordinates. (If the telescope is perfectly aligned with the
To polar-align the telescope:
search the internet. For example, if your latitude is 35° north, set the pointer to 35. Then retighten the latitude knob. The latitude setting should not have to be adjusted again unless you move to a different viewing location some distance away.
3.Loosen the Dec. lock knob (12) and rotate the telescope optical tube (11) until it is parallel with the R.A. axis, as it is in Figure 1. The pointer on the Dec. setting circle (13) should read 90°. Retighten the Dec. lock knob.
4.Loosen the azimuth adjustment knob (23) on the mount and rotate the mount so the telescope tube (and R.A. axis) points roughly at Polaris. If you cannot see Polaris directly from your observing site, consult a compass and rotate the mount so the telescope points north. Retighten the azimuth adjustment knob.
Ursa minor |
|
|
| Polaris |
Ursa major | Cassiopeia |
Figure 3: Finding Polaris
The equatorial mount is now polar aligned.
From this point on in your observing session, you should not make any further adjustments in the azimuth or the latitude of the mount, nor should you move the tripod. Doing so will undo the polar alignment. The telescope should be moved only about its R.A. and Dec. axes.
1.Level the equatorial mount by adjusting the length of the three tripod legs (2).
2.Loosen the latitude adjustment knob (24) and tilt the mount until the pointer on the latitude scale is set at the latitude of your observing site. If you don’t know your latitude, consult a geographical atlas or
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