3. Retighten the counterweight lock knobs. The telescope
is now balanced on the right ascension axis.
4. To balance the telescope on the declination axis, first
tighten 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 Dec. axis. Loosen the tube ring
clamps 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 3c).
6. Position the telescope in the tube rings so it remains
horizontal when you carefully let go with both hands.
This is the balance point for the optical tube with
respect to the Dec. axis (Figure 3d).
7. Retighten the knurled ring clamps.
The telescope is now balanced on both axes. When you
loosen 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
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 4)
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 only the R.A. slow-
motion knob. But first the R.A. axis of the mount must be
aligned with the Earth’s rotational (polar) axis—a process
called polar alignment.
Polar Alignment
For Northern Hemisphere observers, approximate polar
alignment is achieved by pointing the mount’s right ascen-
sion 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 the NCP.
To find Polaris in the sky, look north and locate the pattern
of the Big Dipper (Figure 5). The two stars at the end of the
“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.
5
Figure 4. The SkyView Pro Equatorial Mount, shown from both sides.
Dec. slow-motion
control knob
Dec. setting circle
Front opening
R.A. slow-motion
control knob
a. b.
R.A. set-
ting-circle
Polar axis
finder-scope
(optional)
Dec. lock lever
R.A. lock lever
Latitude scale
Latitude
adjustment
L-bolts
Figure 5. 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).
Big Dipper
(in Ursa Major)
Little Dipper
(in Ursa Minor)
Cassiopeia
N.C.P.
Pointer
Stars
Polaris
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