Vixen Sphinx SXP - Manual (Page 56)

HYDRUS
OCTANS
MENSA
VOLANS
CARINA
CENTAURUS
CRUX
CHAMAELEON
MUSCA
DORADO
α
γ
β
δ
β γ 1
γ 2
γ 3
υ
τ
σ
χ
80°
70°
Small Magellanic Cloud
Large Magellanic Cloud
80°
70°
1
1
2
3
Chapter 5 APPLICATION
Polar Alignment in the Southern Hemisphere
1. Directing to the Octans using Small Magellanic Cloud and the Southern Cross (Crux) as pointers
2. Directing to the Octans using the arrangement of stars in the Southern Cross (Crux) as pointers
Octans is a constellation located near the south celestial pole and it can be used to align the Polarie in the southern hemisphere. Unlike
Polaris which is a bright 2nd magnitude star adjacent to the north celestial pole, Octans is made up of dark stars about 5th magnitude on
average. The nearest star to the south celestial pole is Sigma Octantis, which is one of four stars forming a trapezoid in Octans, visible at
5.5th magnitude. There are a few methods to locate inconspicuous Octans using the surrounding stars.
Draw an imaginary line between the center of Small Magellanic Cloud and Beta Crux and divide it at a ratio of one to two. You will find the
four stars of Octans at the divide.
Draw an imaginary line straight through the two stars (Alpha and Beta Crux) of the Southern Cross making the vertical line of the cross toward
Small Magellanic Cloud. You will find the four stars of Octans at a place about 4.5 times extended from the span of the two stars.
3. Directing the Octans using Small Magellanic Cloud, Beta Hydrus and Gamma Octantis as pointers
If you cast your eyes a little toward Crux from Small Magellanic Cloud, you will see Beta Hydrus. Going southward from Beta Hydrus will find
you Gamma Octans which consists of a row of three stars. Continue on your eyes by the same distance toward the Southern Cross and you
will find the four stars of Octans.
Note: The orientation of the Octanschanges depending on the season of year.
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