Omicron1 Centauri

For other star systems with this Bayer designation, see Omicron Centauri.
ο1 Centauri


Location of ο1 Cen (circled)

Observation data
Epoch J2000.0      Equinox J2000.0
Constellation Centaurus
Right ascension 11h 31m 46.07s[1]
Declination −59° 26′ 31.4″[1]
Apparent magnitude (V) +5.13[2]
Characteristics
Spectral type G3 0-Ia[3][4]
B−V color index +1.08[2]
Variable type SRd[5]
Astrometry
Radial velocity (Rv)−20.00[6] km/s
Proper motion (μ) RA: -4.31 ± 0.28[1] mas/yr
Dec.: 1.72 ± 0.28[1] mas/yr
Parallax (π)0.57 ± 0.32[1] mas
Distanceapprox. 6,000 ly
(approx. 1,800 pc)
Absolute magnitude (MV)−9.0[4]
Details
Surface gravity (log g)0.19[7] cgs
Temperature4,873[8] K
Other designations
HR 4441, HD 100261, CD−58°4100, HIP 56243, SAO 239145, GC 15818, CCDM J11318-5927, AAVSO 1127-58
Database references
SIMBADdata

Omicron1 Centauri (ο1 Cen, ο1 Centauri) is a star in the constellation Centaurus. It is approximately 6,000 light years from Earth.

ο1 Centauri is a yellow G-type supergiant or hypergiant with a mean apparent magnitude of +5.13. It is classified as a semiregular variable star and its brightness varies from magnitude +5.8 to +6.6 with a period of 200 days.[5] Other studies have reported only small brightness variations.[9][10] The spectral type os often given as G3 O-Ia indicating a highly luminous mass-losing hypergiant star. It has also be classified as F8 Ia0[11] and F7 Ia/ab.[12] The size, luminosity, and distance are equally uncertain.

ο1 Cen forms a very close naked eye double star with ο2 Cen, a hotter supergiant that may be physically associated. ο1 has an 11th magnitude companion only 13.5" distant.[13]

References

  1. 1 2 3 4 5 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. Vizier catalog entry
  2. 1 2 Malyuto, V.; Schmidt-Kaler, T. (1997). "Quantitative spectral classification based on photoelectric spectrum scanner measurements of F-K stars". Astronomy and Astrophysics 325: 693. Bibcode:1997A&A...325..693M.
  3. ↑ Keenan, P. C.; Pitts, R. E. (1980). "Revised MK spectral types for G, K, and M stars". Astrophysical Journal Supplement Series 42: 541. Bibcode:1980ApJS...42..541K. doi:10.1086/190662.
  4. 1 2 Arellano Ferro, A.; Giridhar, Sunetra; Goswami, Aruna (1991). "A new discussion on the M(v) - W(O I 7774 A) relationship for F-G stars in the light of high-resolution data". Monthly Notices of the Royal Astronomical Society (ISSN 0035-8711) 250: 1. Bibcode:1991MNRAS.250....1A. doi:10.1093/mnras/250.1.1.
  5. 1 2 Samus, N. N.; Durlevich, O. V.; et al. (2009). "VizieR Online Data Catalog: General Catalogue of Variable Stars (Samus+ 2007-2013)". VizieR On-line Data Catalog: B/gcvs. Originally published in: 2009yCat....102025S 1. Bibcode:2009yCat....102025S.
  6. ↑ Gontcharov, G. A. (2006). "Pulkovo Compilation of Radial Velocities for 35 495 Hipparcos stars in a common system". Astronomy Letters 32 (11): 759. Bibcode:2006AstL...32..759G. doi:10.1134/S1063773706110065.
  7. ↑ Mallik, Sushma V. (1998). "The central depth of the Ca II triplet lines as a discriminant of chromospheric activity in late type stars". Bulletin of the Astronomical Society of India 26: 479. Bibcode:1998BASI...26..479M.
  8. ↑ McDonald, I.; Zijlstra, A. A.; Boyer, M. L. (2012). "Fundamental parameters and infrared excesses of Hipparcos stars". Monthly Notices of the Royal Astronomical Society 427: 343. arXiv:1208.2037. Bibcode:2012MNRAS.427..343M. doi:10.1111/j.1365-2966.2012.21873.x.
  9. ↑ Friedrich, D.; Schoffel, E. (1971). "New Bright Southern Variable Stars". Information Bulletin on Variable Stars 558: 1. Bibcode:1971IBVS..558....1F.
  10. ↑ Sterken, C.; Manfroid, J.; Anton, K.; Barzewski, A.; Bibo, E.; Bruch, A.; Burger, M.; Duerbeck, H. W.; Duemmler, R.; Heck, A.; Hensberge, H.; Hiesgen, M.; Inklaar, F.; Jorissen, A.; Juettner, A.; Kinkel, U.; Liu, Zongli; Mekkaden, M. V.; Ng, Y. K.; Niarchos, P.; Puttmann, M.; Szeifert, T.; Spiller, F.; Van Dijk, R.; Vogt, N.; Wanders, I. (1993). "Longterm Photometry of Variables at ESO - Part Two - the Second Data Catalogue 1986-1990". Astronomy and Astrophysics Supplement 102: 79. Bibcode:1993A&AS..102...79S.
  11. ↑ Mantegazza, L. (1992). "Luminosities of yellow supergiants from near-infrared spectra - Calibration through Magellanic Cloud stars". Astronomy and Astrophysics 265: 527. Bibcode:1992A&A...265..527M.
  12. ↑ Sowell, James R. (1990). "A survey of Balmer-line profiles and IRAS fluxes in forty yellow supergiants". Astronomical Journal 100: 834. Bibcode:1990AJ....100..834S. doi:10.1086/115567.
  13. ↑ Mason, Brian D.; Wycoff, Gary L.; Hartkopf, William I.; Douglass, Geoffrey G.; Worley, Charles E. (2001). "The 2001 US Naval Observatory Double Star CD-ROM. I. The Washington Double Star Catalog". The Astronomical Journal 122 (6): 3466. Bibcode:2001AJ....122.3466M. doi:10.1086/323920.
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