Astronomy:HD 85859
| Observation data Equinox J2000.0]] (ICRS) | |
|---|---|
| Constellation | Hydra[1] |
| Right ascension | 09h 54m 12.32596s[2] |
| Declination | −25° 55′ 56.3631″[2] |
| Apparent magnitude (V) | 4.88[3] |
| Characteristics | |
| Evolutionary stage | red clump[4] |
| Spectral type | K2+ III CN0.5[5] |
| B−V color index | 1.23[3] |
| Astrometry | |
| Radial velocity (Rv) | 50.5[3] km/s |
| Proper motion (μ) | RA: −187.764[2] mas/yr Dec.: +52.746[2] mas/yr |
| Parallax (π) | 12.5809 ± 0.2161[2] mas |
| Distance | 259 ± 4 ly (79 ± 1 pc) |
| Absolute magnitude (MV) | −0.23[1] |
| Details | |
| Mass | 1.55[3] M☉ |
| Luminosity | 178[3] L☉ |
| Surface gravity (log g) | 2.35[6] cgs |
| Temperature | 4,415±25[3] K |
| Metallicity [Fe/H] | −0.03[6] dex |
| Age | 4.34[3] Gyr |
| Other designations | |
| Database references | |
| SIMBAD | data |
HD 85859 is a single[8] star in the equatorial constellation of Hydra. It has an apparent visual magnitude of 4.88,[3] 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,[2] is 259 light years. It is moving away from the Earth with a heliocentric radial velocity of 50.5 km/s.[3]
The stellar classification of the visible component is K2+ III CN0.5,[5] which matches an evolved K-type giant star with a mild overabundance of CN in the atmosphere. At the age of 4.34[3] 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.[4] The star has 1.55[3] times the mass of the Sun and is radiating 178[3] times the Sun's luminosity from its enlarged photosphere at an effective temperature of 4,415 K.[3]
References
- ↑ 1.0 1.1 Anderson, E.; Francis, Ch. (2012), "XHIP: An extended hipparcos compilation", Astronomy Letters 38 (5): 331, doi:10.1134/S1063773712050015, Bibcode: 2012AstL...38..331A.
- ↑ 2.0 2.1 2.2 2.3 2.4 2.5 Brown, A. G. A. (August 2018). "Gaia Data Release 2: Summary of the contents and survey properties". Astronomy & Astrophysics 616: A1. doi:10.1051/0004-6361/201833051. Bibcode: 2018A&A...616A...1G.
- ↑ 3.00 3.01 3.02 3.03 3.04 3.05 3.06 3.07 3.08 3.09 3.10 3.11 3.12 Luck, R. Earle (2015). "Abundances in the Local Region. I. G and K Giants". Astronomical Journal 150 (3). doi:10.1088/0004-6256/150/3/88. Bibcode: 2015AJ....150...88L.
- ↑ 4.0 4.1 Alves, David R. (August 2000), "K-Band Calibration of the Red Clump Luminosity", The Astrophysical Journal 539 (2): 732–741, doi:10.1086/309278, Bibcode: 2000ApJ...539..732A.
- ↑ 5.0 5.1 Keenan, P.; McNeil, R. (October 1989), "The Perkins catalog of revised MK types for the cooler stars", Astrophysical Journal Supplement Series 71: 245–266, doi:10.1086/191373, Bibcode: 1989ApJS...71..245K
- ↑ 6.0 6.1 Soubiran, C. et al. (June 2010), "The PASTEL catalogue of stellar parameters", Astronomy and Astrophysics 515: A111, doi:10.1051/0004-6361/201014247, Bibcode: 2010A&A...515A.111S.
- ↑ "HD 85859". SIMBAD. Centre de données astronomiques de Strasbourg. http://simbad.u-strasbg.fr/simbad/sim-basic?Ident=HD+85859.
- ↑ 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, doi:10.1111/j.1365-2966.2008.13596.x, Bibcode: 2008MNRAS.389..869E.
 |  |
