Key facts
- Constellation
- Octans
- Right ascension
- 21 08 46.86357
- Declination
- −88 ° 57 ′ 23.3983 ″
- Spectral type
- F0 IV
- U b color index
- +0.13
- B v color index
- +0.26
- Variable type
- δ Sct
via Wikipedia infobox
~4 min read
Encyclopedic overview
Sigma Octantis is a solitary star in the Octans constellation that forms the pole star of the Southern Hemisphere. Its name is also written as σ Octantis, abbreviated as Sigma Oct or σ Oct, and it is officially named Polaris Australis (/poʊˈlɛərɪs ɔːˈstreɪlɪs/). The star is positioned one degree away from the southern celestial pole of the Southern Hemisphere, lying in a nearly opposite direction to the North Star on the celestial sphere.
Located approximately 294 light-years from Earth, it is classified as a subgiant with a spectral type of F0 IV. Sigma Octantis has an apparent magnitude of 5.5, but is slightly variable and is classified as a Delta Scuti variable.
Excerpted from Wikipedia’s “Sigma Octantis” article, available under the CC BY-SA 4.0 licence.