English nameOctant

No star of the constellation exceeds the magnitude 3,5.

DescriptionThis constellation contains the South Pole: it is not very evident and its brightest stars are of fourth magnitude.

The South Pole nearest star that is visible to the naked eye is sigma Octantis, a white star of magnitude 5,5: today it is at about a degree from the Pole. Because of the precession the Pole is moving toward Chamaeleon, in a zone which is very poor in stars: probably, within about 2000 years, the southern polar star will be delta Chamaeleontis.

To find the exact position of the South Pole, it is necessary to consider that it forms, with the stars tau and chi Octantis, an almost equilateral triangle centered on sigma Octantis.

and history
The constellation was drawn by Nicolas Louis de La Caille in 1756. It represents the tool invented by John Hadley in 1731.

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