6 Hydrae
| Observation data Epoch J2000.0 Equinox J2000.0 | |
|---|---|
| Constellation | Hydra |
| Right ascension | 08h 40m 01.47182s[1] |
| Declination | −12° 28′ 31.3433″[1] |
| Apparent magnitude (V) | 4.98[2] |
| Characteristics | |
| Evolutionary stage | giant |
| Spectral type | K3 III[3] |
| B−V color index | 1.415±0.001[2] |
| Astrometry | |
| Radial velocity (Rv) | −7.8±0.6[4] km/s |
| Proper motion (μ) | RA: −81.619[1] mas/yr Dec.: −1.646[1] mas/yr |
| Parallax (π) | 8.7394 ± 0.1769 mas[1] |
| Distance | 373 ± 8 ly (114 ± 2 pc) |
| Absolute magnitude (MV) | −0.40[2] |
| Details | |
| Radius | 32.7+0.5 −2.6[1] R☉ |
| Luminosity | 267±6[1] L☉ |
| Surface gravity (log g) | 1.91[5] cgs |
| Temperature | 4,080+173 −30[1] K |
| Metallicity [Fe/H] | −0.21[5] dex |
| Other designations | |
| Database references | |
| SIMBAD | data |
6 Hydrae is a single[7] star in the equatorial constellation of Hydra,[6] located 373 light-years away from the Sun.[1] It has the Bayer designation a Hydrae; 6 Hydrae is the Flamsteed designation. This object is visible to the naked eye as a faint, orange-hued star with an apparent visual magnitude of 4.98.[2] It is moving closer to the Earth with a heliocentric radial velocity of −8 km/s.[4] Eggen (1995) listed it as a proper motion candidate for membership in the IC 2391 supercluster.[8]
This is an aging giant star with a stellar classification of K3 III,[3] which indicates it has exhausted the hydrogen at its core and evolved away from the main sequence. As a consequence, it has expanded to 33[1] times the radius of the Sun. The star is radiating 267[1] times the luminosity of the Sun from its swollen photosphere at an effective temperature of 4,080 K.[1]
References
[edit]- ^ a b c d e f g h i j k l 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 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.
- ^ a b Houk, Nancy; Smith-Moore, M. (1978), Michigan catalogue of two-dimensional spectral types for the HD stars, vol. 4, Ann Arbor: Dept. of Astronomy, University of Michigan, Bibcode:1988mcts.book.....H.
- ^ a b de Bruijne, J. H. J.; Eilers, A.-C. (October 2012), "Radial velocities for the HIPPARCOS-Gaia Hundred-Thousand-Proper-Motion project", Astronomy & Astrophysics, 546: 14, arXiv:1208.3048, Bibcode:2012A&A...546A..61D, doi:10.1051/0004-6361/201219219, S2CID 59451347, A61.
- ^ a b McWilliam, Andrew (December 1990), "High-resolution spectroscopic survey of 671 GK giants. I - Stellar atmosphere parameters and abundances", Astrophysical Journal Supplement Series, 74: 1075–1128, Bibcode:1990ApJS...74.1075M, doi:10.1086/191527.
- ^ a b "6 Hya". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2019-04-23.
- ^ Eggleton, P. P.; Tokovinin, A. A. (2008), "A catalogue of multiplicity among bright stellar systems", Monthly Notices of the Royal Astronomical Society, 389 (2): 869, arXiv:0806.2878, Bibcode:2008MNRAS.389..869E, doi:10.1111/j.1365-2966.2008.13596.x, S2CID 14878976.
- ^ Eggen, Olin J. (December 1995), "Reality Tests of Superclusters in the Young Disk Population", Astronomical Journal, 110: 2862, Bibcode:1995AJ....110.2862E, doi:10.1086/117734.