HD 85859
  | |
| Observation data Epoch J2000 Equinox ICRS | |
|---|---|
| Constellation | Hydra |
| Right ascension | 09h 54m 12.32596s |
| Declination | −25° 55′ 56.3631″ |
| Apparent magnitude (V) | 4.88 |
| Characteristics | |
| Evolutionary stage | red clump |
| Spectral type | K2+ III CN0.5 |
| B−V color index | 1.23 |
| Astrometry | |
| Radial velocity (Rv) | 50.5 km/s |
| Proper motion (μ) | RA: −187.764 mas/yr Dec.: +52.746 mas/yr |
| Parallax (π) | 12.5809±0.2161 mas |
| Distance | 259 ± 4 ly (79 ± 1 pc) |
| Absolute magnitude (MV) | −0.23 |
| Details | |
| Mass | 1.55 M☉ |
| Luminosity | 178 L☉ |
| Surface gravity (log g) | 2.35 cgs |
| Temperature | 4,415±25 K |
| Metallicity [Fe/H] | −0.03 dex |
| Age | 4.34 Gyr |
| Other designations | |
| CD−25°7585, FK5 2792, HD 85859, HIP 48559, HR 3919, SAO 178158 | |
| Database references | |
| SIMBAD | data |
HD 85859 is a single star in the equatorial constellation of Hydra. It has an apparent visual magnitude of 4.88, which is bright enough to be visible to the naked eye. The distance to this star, as estimated from its annual parallax shift of 12.6 mas, is 259 light years. It is moving away from the Earth with a heliocentric radial velocity of 50.5 km/s.
The stellar classification of the visible component is K2+ III CN0.5, which matches an evolved K-type giant star with a mild overabundance of CN in the atmosphere. At the age of 4.34 billion years, it is a red clump star, which indicates it is on the horizontal branch and is generating energy through helium fusion at its core. The star has 1.55 times the mass of the Sun and is radiating 178 times the Sun's luminosity from its enlarged photosphere at an effective temperature of 4,415 K.
References
- 1 2 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.
- 1 2 3 4 5 6 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.
- 1 2 3 4 5 6 7 8 9 10 11 12 13 Luck, R. Earle (2015). "Abundances in the Local Region. I. G and K Giants". Astronomical Journal. 150 (3). 88. arXiv:1507.01466. Bibcode:2015AJ....150...88L. doi:10.1088/0004-6256/150/3/88. S2CID 118505114.
- 1 2 Alves, David R. (August 2000), "K-Band Calibration of the Red Clump Luminosity", The Astrophysical Journal, 539 (2): 732–741, arXiv:astro-ph/0003329, Bibcode:2000ApJ...539..732A, doi:10.1086/309278, S2CID 16673121.
- 1 2 Keenan, P.; McNeil, R. (October 1989), "The Perkins catalog of revised MK types for the cooler stars", Astrophysical Journal Supplement Series, 71: 245–266, Bibcode:1989ApJS...71..245K, doi:10.1086/191373
- 1 2 Soubiran, C.; et al. (June 2010), "The PASTEL catalogue of stellar parameters", Astronomy and Astrophysics, 515: A111, arXiv:1004.1069, Bibcode:2010A&A...515A.111S, doi:10.1051/0004-6361/201014247, S2CID 118362423.
- ↑ "HD 85859". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2018-07-26.
- ↑ 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.
