![6.Setting Up and Using the Equatorial Mount](/images/new-backgrounds/102026/1020269x1.webp)
2. Now loosen both counterweight lock knobs and slide the |
weights along the shaft until they exactly counterbalance |
the telescope (Figure 4a). That’s the point at which the |
shaft remains horizontal even when you let go with both |
hands (Figure 4b). If the telescope refuses to balance |
than you have either too much or too little counterweight. |
Remove a counterweight, or add optional counterweights |
if needed. |
3. Retighten the counterweight lock knobs. The telescope is |
now balanced on the right ascension axis. |
The telescope is now balanced on both axes. When you loos- en the lock lever on one or both axes and manually point the telescope, it should move without resistance and should not drift from where you point it.
6.Setting Up and Using the Equatorial Mount
4. | To balance the telescope on the declination axis, first tight- |
| en the R.A. lock lever, with the counterweight shaft still in |
| the horizontal position. |
5. | With one hand on the telescope optical tube, loosen the |
| Dec. lock lever. The telescope should now be able to rotate |
| freely about the declination axis. |
6. | Loosen the knurled ring clamps on the tube rings 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) (Figure 4c). |
7. | Position the telescope in the tube rings so it remains hori- |
| zontal when you carefully let go with both hands. This is |
| the balance point for the optical tube with respect to the |
| Dec. axis (Figure 4d). |
8. | Retighten the knurled ring clamps. |
Dec. lock lever (not shown)
Front opening |
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Figure 5. The Atlas
R.A. lock lever
Polar axis finder scope
Latitude scale
Latitude adjustment
a.b.
c.d.
Figure
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 your 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 the built in motor drive. But first the R.A. axis of the mount must be aligned with the Earth’s rotational (polar)
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Big Dipper | N.C.P. | |||
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(in Ursa Major) |
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| Polaris |
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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).
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