Octans Haštakân (#) Fr.: Octant The Octant. A faint and obscure constellation, at 21h right ascension, 80° south declination, containing the south celestial pole. Its star Sigma Octantis is the closest naked-eye star to the pole, but it is so faint (magnitude 5.47) that it is practically useless as a polar star for navigation purposes. Abbreviation: Oct; Genitive: Octantis. It was introduced by the French astronomer Nicolas Louis de Lacaille (1713-1762). From L.L. octans "eighth part of a circle," from → octa-, oct- + -ans, as in quadrans; → quadrant. Haštakân, → octant. |