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Epsilon Circini 
Summary
Epsilon Circini, Latinized from ε Circini, is a solitary[6] star located in the southern constellation of Circinus. It is faintly visible to the naked eye, having an apparent visual magnitude of 4.86.[2] The distance to this star, as determined by a measured annual parallax shift of 7.63 mas, is around 428 light years. It is drifting closer to the Sun with a radial velocity of −4 km/s.[1]
| Observation data Epoch J2000.0 Equinox J2000.0 (ICRS) | |
|---|---|
| Constellation | Circinus |
| Right ascension | 15h 17m 38.88983s[1] |
| Declination | −63° 36′ 37.6734″[1] |
| Apparent magnitude (V) | 4.86[2] |
| Characteristics | |
| Spectral type | K2.5 III[3] |
| U−B color index | +1.32[2] |
| B−V color index | +1.260±0.004[4] |
| Astrometry | |
| Radial velocity (Rv) | −4.22±0.42[1] km/s |
| Proper motion (μ) | RA: +4.624[1] mas/yr Dec.: +8.728[1] mas/yr |
| Parallax (π) | 7.6263 ± 0.1503 mas[1] |
| Distance | 428 ± 8 ly (131 ± 3 pc) |
| Absolute magnitude (MV) | −0.63[4] |
| Details | |
| Radius | 28.5+1.2 −3.0[1] R☉ |
| Luminosity | 289.6±6.6[1] L☉ |
| Temperature | 4,457+252 −87[1] K |
| Other designations | |
| Database references | |
| SIMBAD | data |
This is an evolved K-type giant star with a stellar classification of K2.5 III.[3] With the supply of hydrogen at its core exhausted, the star has cooled and expanded to 28.5 times the girth of the Sun. It radiates about 290 times the solar luminosity from its photosphere at an effective temperature of 4,457 K.[1]
References edit
- ^ a b c d e f g h i j k 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 Johnson, H. L.; et al. (1966), "UBVRIJKL photometry of the bright stars", Communications of the Lunar and Planetary Laboratory, 4 (99): 99, Bibcode:1966CoLPL...4...99J.
- ^ a b Landi Dessy, J.; Keenan, P. C. (November 1966), "Spectral Types on the MK System for Forty-Three Bright Southern Stars, K2-M6", Astrophysical Journal, 146: 587, Bibcode:1966ApJ...146..587L, doi:10.1086/148925.
- ^ 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.
- ^ "eps Cir -- Star", SIMBAD Astronomical Database, Centre de Données astronomiques de Strasbourg, retrieved 2017-01-18.
- ^ 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.