Sigma Capricorni
| Observation data Epoch J2000.0 Equinox J2000.0 (ICRS) | |
|---|---|
| Constellation | Capricornus[1] |
| Right ascension | 20h 19m 23.604s[2] |
| Declination | −19° 07′ 06.69″[2] |
| Apparent magnitude (V) | +5.31[3] |
| Characteristics | |
| Spectral type | K2 III[4] |
| U−B color index | +1.56[3] |
| B−V color index | +1.43[3] |
| Astrometry | |
| Radial velocity (Rv) | −9.64±0.16[5] km/s |
| Proper motion (μ) | RA: +5.034 mas/yr[2] Dec.: −10.825 mas/yr[2] |
| Parallax (π) | 3.4448±0.0987 mas[2] |
| Distance | 950 ± 30 ly (290 ± 8 pc) |
| Absolute magnitude (MV) | −2.38[1] |
| Details | |
| Mass | 6.3±0.7[6] M☉ |
| Radius | 67.5+4.2 −6.0[5] R☉ |
| Luminosity | 1,392±64[5] L☉ |
| Temperature | 4,292+204 −127[5] K |
| Age | 60.5±17.2[6] Myr |
| Other designations | |
| σ Cap, CD−19°5776, FK5 3625, HD 193150, HIP 100195, HR 7761, SAO 163445, WDS J20194-1907A[7] | |
| Database references | |
| SIMBAD | data |
Sigma Capricorni is a solitary,[8] orange-hued star in the southern constellation of Capricornus,[7] 0.5 degree north of the ecliptic. Its name is a Bayer designation that is Latinized from σ Capricorni, and abbreviated Sigma Cap or σ Cap. This star is visible to the naked eye as a dim, orange-hued star with an apparent visual magnitude of +5.31.[3] The star is about 950 ly (290 pc) 1,070 light years away from the Sun based on parallax, but is drifting closer with a radial velocity of −9.6 km/s.[5]
This is an evolved, K-type giant star with a stellar classification of K2 III.[4] Having exhausted the supply of hydrogen at its core, it has expanded and now has around 67.5[5] times the girth of the Sun. The star is about 60.5[6] million years old with 6.3[6] times the mass of the Sun. It is radiating 1,392[5] times the luminosity of the Sun from its swollen photosphere at an effective temperature of 4,292 K.[5]
A magnitude 9.43 visual companion is at an angular separation of 55.90″ along a position angle of 179°, as of 2016.[9]
References
- ^ 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. XHIP record for this object at VizieR.
- ^ a b c d Vallenari, A.; et al. (Gaia collaboration) (2023), "Gaia Data Release 3. Summary of the content and survey properties", Astronomy and Astrophysics, 674: A1, arXiv:2208.00211, Bibcode:2023A&A...674A...1G, doi:10.1051/0004-6361/202243940, S2CID 244398875. Gaia DR3 record for this source at VizieR.
- ^ a b c d Fernie, J. D. (May 1983), "New UBVRI photometry for 900 supergiants", Astrophysical Journal Supplement Series, 52: 7–22, Bibcode:1983ApJS...52....7F, doi:10.1086/190856.
- ^ a b Houk, N.; Smith-Moore, M. (1988), Michigan Catalogue of Two-dimensional Spectral Types for the HD Stars, vol. 4, Bibcode:1988mcts.book.....H.
- ^ a b c d e f g h Brown, A. G. A.; et al. (Gaia collaboration) (August 2018), "Gaia Data Release 2: Summary of the contents and survey properties", Astronomy & Astrophysics, 616, A1, arXiv:1804.09365, Bibcode:2018A&A...616A...1G, doi:10.1051/0004-6361/201833051 Gaia DR2 record for this source at VizieR.
- ^ a b c d Tetzlaff, N.; et al. (January 2011), "A catalogue of young runaway Hipparcos stars within 3 kpc from the Sun", Monthly Notices of the Royal Astronomical Society, 410 (1): 190–200, arXiv:1007.4883, Bibcode:2011MNRAS.410..190T, doi:10.1111/j.1365-2966.2010.17434.x, S2CID 118629873.
- ^ a b "* sig Cap", SIMBAD, Centre de données astronomiques de Strasbourg, retrieved 2017-05-12.
- ^ Eggleton, P. P.; Tokovinin, A. A. (September 2008), "A catalogue of multiplicity among bright stellar systems", Monthly Notices of the Royal Astronomical Society, 389 (2): 869–879, arXiv:0806.2878, Bibcode:2008MNRAS.389..869E, doi:10.1111/j.1365-2966.2008.13596.x, S2CID 14878976.
- ^ Mason, B. D.; et al. (2014), "The Washington Visual Double Star Catalog", The Astronomical Journal, 122 (6): 3466, Bibcode:2001AJ....122.3466M, doi:10.1086/323920