10
Locate Polaris and place it in the center of the Polarscope by
adjusting the Altitude and Azimuth of the mount. Place
Polaris directly under the cross in the center of the reticle
(Fig.h-1). Rotate the mount one half turn about the R.A. axis.
Polaris should remain under the cross in the center of the
reticle. If it does not, the reticle is not centered on the R.A.
axis of the mount.
To move the reticle, adjust the three small Allen screws
(Fig.h-2) on the polar scope. Make small adjustments by
moving only two of the screws at a time. Adjust the screws to
move Polaris
half the distance back to the center of the
reticle. This is because Polaris started in the center of the
reticle. By rotating the mount 180 degrees, Polaris moved
exactly twice the distance between the center of the reticle
and the center of rotation. The center of rotation lies midway
between the center of the reticle and the new position of
Polaris. Do not turn any of the set screws more than one
quarter turn at a time or the reticle will disengage from the
set screws. Do not tighten these screws too much or the
stress will fracture the lenses in the polar scope.
Now re-center Polaris under the cross in the middle of the
reticle using the azimuth and altitude adjustments. Repeat
the entire procedure until Polaris remains in the center of the
reticle when the mount is rotated about the R.A. axis.
With some practice, you should be able to align the reticle
with the R.A. axis to within about 2 or 3 arc-minutes. You
should never have to make this adjustment again, unless the
polar scope has been dropped, disassembled, or if the polar
scope is to be used on another mount. If Polaris is not visible
from your area, you can use a distant object such as the top
of a telephone pole, or a distant mountain-top. These objects
are larger than the image of a star, so they will not provide as
accurate an alignment.
Using the Polarscope in the Northern Hemisphere
There is only one easily visible star near the North Celestial
Pole. This star is Polaris. The rest of the stars in Ursa Minor
are around Magnitude 5 and require very dark skies to
become visible (Fig.h-3).
Since Polaris is not exactly on the North Celestial Pole, you
need to offset the telescope's R.A. axis from Polaris by a
small amount in the correct direction. There is a radial line in
the Polarscope. Along this line, there are tick marks and a
circle. Rotate the mount in R.A. until this line points towards
Beta-Ursa Minoris (Fig.h-4). If this star can not be seen,
Mizar, the second star in the Big Dipper's handle, can be
used. If these stars can not be seen, point the line in the pole
finder away from the constellation Cassiopeia. Set the lock on
the R.A. axis so the mount does not rotate.
Adjust the mount in Altitude and Azimuth again, until Polaris
is in the circle on the line in the pole finder (Fig.h-4).
2
1
2
3
E
W
20
20
10
10
0
adjust these screws
40'
60'
place Polaris here
Cassiopeia
Mizar
Big Dipper
Polaris
Beta-Ursa Minoris
NCP
Fig.h-1
Fig.h-2
Fig.h-3
Summary of Contents for SK P25012EQ6-2IN
Page 1: ...SK P25012EQ6 2IN...
