Astronomy:Eta Circini
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Short description: Star in the constellation Circinus
| Observation data Equinox J2000.0]] (ICRS) | |
|---|---|
| Constellation | Circinus |
| Right ascension | 15h 04m 48.18600s[1] |
| Declination | −64° 01′ 52.8611″[1] |
| Apparent magnitude (V) | 5.17[2] |
| Characteristics | |
| Spectral type | G8 III[3] |
| B−V color index | +0.93[2] |
| Astrometry | |
| Radial velocity (Rv) | 44.8±0.8[4] km/s |
| Proper motion (μ) | RA: +102.65[1] mas/yr Dec.: +9.35[1] mas/yr |
| Parallax (π) | 11.82 ± 0.30[1] mas |
| Distance | 276 ± 7 ly (85 ± 2 pc) |
| Absolute magnitude (MV) | +0.52[5] |
| Details | |
| Luminosity | 64[6] L☉ |
| Surface gravity (log g) | 2.69±0.05[7] cgs |
| Temperature | 4,954±22[7] K |
| Metallicity [Fe/H] | −0.37±0.02[7] dex |
| Other designations | |
| Database references | |
| SIMBAD | data |
Eta Circini, Latinized from η Circini, is the Bayer designation for a solitary[9] star located in the southern constellation of Circinus. It is faintly visible to the naked eye with an apparent visual magnitude of 5.17.[2] The distance to this star, as determined from an annual parallax shift of 11.82 mas,[1] is around 276 light years.
This is an evolved G-type giant star with a stellar classification of G8 III.[3] It is radiating an estimated 64[6] times the solar luminosity from its outer atmosphere at an effective temperature of 4,954 K.[7]
References
- ↑ 1.0 1.1 1.2 1.3 1.4 1.5 van Leeuwen, F. (2007), "Validation of the new Hipparcos reduction", Astronomy and Astrophysics 474 (2): 653–664, doi:10.1051/0004-6361:20078357, Bibcode: 2007A&A...474..653V.
- ↑ 2.0 2.1 2.2 Corben, P. M.; Stoy, R. H. (1968), "Photoelectric Magnitudes and Colours for Bright Southern Stars", Monthly Notes of the Astronomical Society of Southern Africa 27: 11, Bibcode: 1968MNSSA..27...11C.
- ↑ 3.0 3.1 Houk, Nancy; Cowley, A. P. (1979), University of Michigan Catalogue of two-dimensional spectral types for the HD stars, 1, Ann Arbor, Michigan: Department of Astronomy, University of Michigan, Bibcode: 1978mcts.book.....H.
- ↑ Gontcharov, G. A. (November 2006), "Pulkovo Compilation of Radial Velocities for 35,495 Hipparcos stars in a common system", Astronomy Letters 32 (11): 759–771, doi:10.1134/S1063773706110065, Bibcode: 2006AstL...32..759G.
- ↑ Anderson, E.; Francis, Ch. (2012), "XHIP: An extended hipparcos compilation", Astronomy Letters 38 (5): 331, doi:10.1134/S1063773712050015, Bibcode: 2012AstL...38..331A.
- ↑ 6.0 6.1 McDonald, I. et al. (2012), "Fundamental Parameters and Infrared Excesses of Hipparcos Stars", Monthly Notices of the Royal Astronomical Society 427 (1): 343–57, doi:10.1111/j.1365-2966.2012.21873.x, Bibcode: 2012MNRAS.427..343M.
- ↑ 7.0 7.1 7.2 7.3 Alves, S. et al. (April 2015), "Determination of the spectroscopic stellar parameters for 257 field giant stars", Monthly Notices of the Royal Astronomical Society 448 (3): 2749–2765, doi:10.1093/mnras/stv189, Bibcode: 2015MNRAS.448.2749A.
- ↑ "eta Cir". SIMBAD. Centre de données astronomiques de Strasbourg. http://simbad.u-strasbg.fr/simbad/sim-basic?Ident=eta+Cir.
- ↑ 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, doi:10.1111/j.1365-2966.2008.13596.x, Bibcode: 2008MNRAS.389..869E.
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