12
Figure 3A
For the most part, to find astronomical objects you’ll be using the right ascension axis, as polar alignment virtually
eliminates the need to adjust the declination axis. To track objects continuously, adjustments must be made with the
right ascension cable, otherwise the rotation of the earth will cause the object you’re viewing to drift out of your field
of view.
The method of polar alignment described above is adequate for casual observing. More precise methods of polar
alignment are available, and most astronomy or telescope textbooks describe these procedures.
Look at the North Star after doing the polar alignment procedure given here - your declination setting circle should
read 90º.
S
S
E
E
T
T
T
T
I
I
N
N
G
G
C
C
I
I
R
R
C
C
L
L
E
E
S
S
The setting circles are dials, or gauges, for right ascension and declination that allow you to locate a celestial object
easily using its coordinates, as listed in a star chart or atlas.
The declination setting circle is scaled in degrees and the right ascension setting circle is laid out in increments of
minutes. The setting circles will assist you to get close to your target, but not directly on it. It’s important to note
that the accuracy of your polar alignment will affect the accuracy of your setting circles readings.
The declination setting circle is set at the factory and won’t require adjustment if it reads accurately. The right
ascension setting circle must be aligned. Choose a bright and easy to find star on a star chart, and note its right
ascension and declination coordinates. Find the star and center it first with the Star Pointer finderscope, then in the
telescope. Rotate the right ascension circle to match the coordinates of the star with the indicator mark.
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