Delta Octantis


δ Octantis
Octans constellation map.svg
Red circle.svg
Location of δ Octantis (circled)
Observation data
Epoch J2000      Equinox J2000
Constellation Octans
Right ascension 14h 26m 55.23244s[1]
Declination −83° 40′ 04.3868″[1]
Apparent magnitude (V) 4.31[2]
Spectral type K2III[3]
U−B color index +1.45[4]
B−V color index +1.31[4]
Radial velocity (Rv)+4.60[5] km/s
Proper motion (μ) RA: -96.12[1] mas/yr
Dec.: -13.27[1] mas/yr
Parallax (π)10.91 ± 0.14[1] mas
Distance299 ± 4 ly
(92 ± 1 pc)
Absolute magnitude (MV)−0.35 ± 0.09[6]
Mass1.06[5] M
Radius24.61[5] R
Luminosity271[2] L
Surface gravity (log g)1.89[5] cgs
Temperature4,311[5] K
Metallicity [Fe/H]-0.42[5] dex
Rotational velocity (v sin i)1.1[7] km/s
Other designations
CD-83 189, GC 19349, HIP 70638, HR 5339, HD 124882, NSV 6636, SAO 258698
Database references

δ Octantis, Latinised as Delta Octantis, has the distinction of being Saturn's southern pole star.[8] An orange giant of class K2III,[3] it has 1.2 times the mass of the Sun and about 25 times the Sun's radius. This star is about 4.3 billion years old, which is similar to the age of the Sun.[6]


In Chinese caused by adaptation of the European southern hemisphere constellations into the Chinese system, 異雀 (Yì Què), meaning Exotic Bird, refers to an asterism consisting of δ Octantis, ζ Apodis, ι Apodis, β Apodis, γ Apodis, δ1 Apodis, η Apodis, α Apodis and ε Apodis. Consequently, δ Octantis itself is known as 異雀五 (Yì Què wǔ, English: the Fifth Star of Exotic Bird.)[9]


  1. ^ a b c d e Van Leeuwen, F. (2007). "Validation of the new Hipparcos reduction". Astronomy and Astrophysics. 474 (2): 653–664. arXiv:0708.1752. Bibcode:2007A&A...474..653V. doi:10.1051/0004-6361:20078357. S2CID 18759600. Vizier catalog entry
  2. ^ a b Anderson, E.; Francis, Ch. (2012). "XHIP: An extended hipparcos compilation". Astronomy Letters. 38 (5): 331. arXiv:1108.4971. Bibcode:2012AstL...38..331A. doi:10.1134/S1063773712050015. S2CID 119257644. Vizier catalog entry
  3. ^ a b Hoffleit, D.; Warren, W. H. (1995). "VizieR Online Data Catalog: Bright Star Catalogue, 5th Revised Ed. (Hoffleit+, 1991)". VizieR On-line Data Catalog: V/50. Originally Published in: 1964BS....C......0H. 5050. Bibcode:1995yCat.5050....0H.
  4. ^ a b Mallama, A. (2014). "Sloan Magnitudes for the Brightest Stars". The Journal of the American Association of Variable Star Observers. 42: 443. Bibcode:2014JAVSO..42..443M.Vizier catalog entry
  5. ^ a b c d e f Jofré, E.; Petrucci, R.; Saffe, C.; Saker, L.; Artur de la Villarmois, E.; Chavero, C.; Gómez, M.; Mauas, P. J. D. (2015). "Stellar parameters and chemical abundances of 223 evolved stars with and without planets". Astronomy & Astrophysics. 574: A50. arXiv:1410.6422. Bibcode:2015A&A...574A..50J. doi:10.1051/0004-6361/201424474. S2CID 53666931. Vizier catalog entry
  6. ^ a b da Silva, L.; et al. (November 2006), "Basic physical parameters of a selected sample of evolved stars", Astronomy and Astrophysics, 458 (2): 609–623, arXiv:astro-ph/0608160, Bibcode:2006A&A...458..609D, doi:10.1051/0004-6361:20065105, S2CID 9341088
  7. ^ De Medeiros, J. R.; Alves, S.; Udry, S.; Andersen, J.; Nordström, B.; Mayor, M. (2014). "A catalog of rotational and radial velocities for evolved stars". Astronomy & Astrophysics. 561: A126. arXiv:1312.3474. Bibcode:2014A&A...561A.126D. doi:10.1051/0004-6361/201220762. S2CID 54046583. Vizier catalog entry
  8. ^ "Octans". UK Astronomy Society. Retrieved 10 October 2011.
  9. ^ (in Chinese) AEEA (Activities of Exhibition and Education in Astronomy) 天文教育資訊網 2006 年 7 月 29 日