Oct - Octans the Octant

Legend for constellation star maps, IAU and Sky & Telescope magazine (Roger Sinnott & Rick Fienberg), cc-by

Intro and Visual description

Octans the Octant is devoid of bright stars, but three faint stars (not numbered by brightness) make a small triangle.

The south celestial pole actually lies within Octans. No RA (visible anytime).  

The nearest easy-to-spot star to the south pole is Beta-Hydri in Hydrus the Little Snake. No brighter star than Achernar (alpha-Eridani) is closer to the south celestial pole, which lies midway between Achernar (Eridanus) and Crux.

One of 17 constellations created by Nicolas Louis de Lacaille in 1756.


Special Stars

Sigma-Octantis, the closest naked-eye star to the south celestial pole. Magnitude: 5.5 (faint). Distance: 121 LY. Declination: -88 degrees 57 minutes 21 seconds. (Is it closer to the south pole than Polaris is to the north pole?)



Constellation Info

Abbr: Oct

Genitive: Octantis

Size: 50 of 88

Evening culmination (9 pm): September

Decl: -85 degrees

Entirely visible from: S of 0° latitude

Partially visible from: between 0° and 15° latitude

Not visible at all from: N of 15° latitude


Bordering constellations:

Constellation - Names

Arabic: الثمن

Chinese: 南極座

English: Octant

French: Octant

German: Oktant

Greek: Οκτάς

Hebrew: אוקטנט

Italian: Ottante

Latin: Octans

Russian: Октант

Spanish: Octante, Bastón

Related Objects

Related Asterisms