| Observation data Epoch J2000.0 Equinox J2000.0 (ICRS) | |
|---|---|
| Constellation | Horologium |
| Right ascension | 02 45 27.47800 |
| Declination | −63° 42′ 16.3925″ |
| Apparent magnitude (V) | +5.743 |
| Characteristics | |
| Spectral type | G8 III/IV |
| B−V color index | +0.929 |
| Astrometry | |
| Radial velocity (Rv) | −18.79±0.16 km/s |
| Proper motion (μ) | RA: +18.913 mas/yr Dec.: −8.742 mas/yr |
| Parallax (π) | 17.7941 ± 0.0592 mas |
| Distance | 183.3 ± 0.6 ly (56.2 ± 0.2 pc) |
| Absolute magnitude (MV) | +1.99 |
| Details | |
| Radius | 5.50+0.11 −0.08 R☉ |
| Luminosity | 16.9±0.1 L☉ |
| Surface gravity (log g) | 3.18±0.05 cgs |
| Temperature | 4,961±24 K |
| Metallicity | −0.26±0.02 dex |
| Other designations | |
| γ Hor, CPD−64° 196, HD 17504, HIP 12871, HR 833, SAO 248642, WDS J02455-6342A | |
| Database references | |
| SIMBAD | data |
γ Horologii, Latinised as Gamma Horologii, is a solitary star in the southern constellation of Horologium. It is just bright enough to be visible to the naked eye as a dim, yellow-hued point of light with an apparent visual magnitude of +5.74. This object is located at a distance of 183 light years from the Sun, but is drifting closer with a radial velocity of −19 km/s.
The stellar classification of this object is G8 III/IV, matching a G-type star with a luminosity class intermediate between a subgiant and giant star. This suggests it has exhausted the supply of hydrogen at its core and is evolving off the main sequence. It has 5.5 times the radius of the Sun and is radiating 17 times the Sun's luminosity from its swelling photosphere at an effective temperature of 4,961 K. The metallicity is sub-solar, indicating a lower abundance of elements more massive than helium, as compared to the Sun.
References
- ^ 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.
- ^ Høg, E.; et al. (March 2000), "The Tycho-2 catalogue of the 2.5 million brightest stars", Astronomy and Astrophysics, 355: L27 – L30, Bibcode:2000A&A...355L..27H, doi:10.1888/0333750888/2862.
- ^ Houk, Nancy; Cowley, A. P. (1979), Michigan catalogue of two-dimensional spectral types for the HD stars, vol. 1, Ann Arbor, Michigan: Dept. of Astronomy, University of Michigan, Bibcode:1978mcts.book.....H.
- 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.
- ^ 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, arXiv:1503.02556, Bibcode:2015MNRAS.448.2749A, doi:10.1093/mnras/stv189.
- "gam Hor". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2019-08-20.
- 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.
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