13
４
σ
Ｏｃ
ｔ
０
２
４
０
１ ０
２
★
★
★
Since there is no mark that points at the South Celestial Pole, you
need to match the polar axis of your AXJ mount with the S.C.P. using
the inconspicuous three stars of Octans in the same area of the sky.
Your goal is to set Sigma Octantis to the edge of the line on the side
of 2014, and both Tau and Chi Octantis are to be set to the middle
of the curved lines of the position scale at the protruded edge on the
side of 15 respectively. (In case of the year 2014)
Turn the polar scope body so that Tau Octantis comes near to the
location of the year 2014 on the scale. And then, Sigma Octantis will
get out of position from the gap between the lines.
Adjust the red light illumination to be dimmer if the reticle is too bright
to see the 5th magnitude stars Sigma and Tau
Celestial south
Celestial south
Center of polar the alignment scope´s field of view
(Center of the rotational axis of the equatorial mount)
Now, Sigma Octantis gets out of place from the designated position but it is not necessary to correct for it at this stage.
The locations of Sigma, Tau and Chi Octantis on the position
scales change year by year due to precession of the Earth.
You need to compensate the locations of the 3 stars on the position scales yearly.
The movement of Chi Octantis from
2014 to 2040 by precession.
The movement of Sigma Octantis
from 2014 to 2040 by precession.
The movement of Tau Octantis from
2014 to 2040 by precession.
