HD 12139 is an orange-hued star in the northern zodiac constellation of Aries. With an apparent visual magnitude of 5.89, it is a dim star that is just visible to the naked eye under good viewing conditions. It is located approximately 351 light-years (107.5 pc) distant from the Sun, based on parallax,[2] but is drifting closer with a radial velocity of −2 km/s.[1] With high probability, it is considered a member of the Hercules stream.[6]
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Aries |
| Right ascension | 01h 59m 35.68394s[1] |
| Declination | 21° 03′ 30.8472″[1] |
| Apparent magnitude (V) | 5.89[2] |
| Characteristics | |
| Spectral type | K0III-IV[3] |
| B−V color index | 1.031±0.015[2] |
| Astrometry | |
| Radial velocity (Rv) | −1.65±0.20[1] km/s |
| Proper motion (μ) | RA: +141.014[1] mas/yr Dec.: -14.643[1] mas/yr |
| Parallax (π) | 9.3049 ± 0.0967 mas[1] |
| Distance | 351 ± 4 ly (107 ± 1 pc) |
| Absolute magnitude (MV) | 0.50[2] |
| Details | |
| Mass | 1.69±0.48[4] M☉ |
| Radius | 11.12+0.34 −0.13[1] R☉ |
| Luminosity | 58.2±0.7[1] L☉ |
| Surface gravity (log g) | 2.50±0.11[4] cgs |
| Temperature | 4,780+120 −70[1] K |
| Metallicity [Fe/H] | −0.02±0.05[4] dex |
| Age | 2.0+1.0 −0.6[4] Gyr |
| Other designations | |
| Database references | |
| SIMBAD | data |
This object is an aging red giant[7] with a stellar classification of K0III-IV,[3] meaning that it has used up its core hydrogen and is expanding. At present it has 11[1] times the girth of the Sun. The star is about two[4] billion years old with 1.7[4] times the mass of the Sun. It is radiating 58[1] times the luminosity of the Sun from its photosphere at an effective temperature of 4,780 K.[1]
A magnitude 9.36 companion is located at an angular separation of 199.70″ from the primary along a position angle of 9°, as of 2015. It is unclear if the two are physically associated.[8]
References
edit- ^ a b c d e f g h i j k l m 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 Yoss, Kenneth M. (November 1961). "Spectral and Luminosity Classifications and Measurements of the Strength of Cyanogen Absorption for Late-Type Stars from Objective-Prism Spectra". Astrophysical Journal. 134: 809. Bibcode:1961ApJ...134..809Y. doi:10.1086/147209.
- ^ a b c d e f Feuillet, Diane K.; et al. (2016). "Determining Ages of APOGEE Giants with Known Distances". The Astrophysical Journal. 817 (1): 40. arXiv:1511.04088. Bibcode:2016ApJ...817...40F. doi:10.3847/0004-637X/817/1/40. S2CID 118675933.
- ^ "HD 12139". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2019-11-13.
- ^ Ramya, P.; et al. (August 2016). "Chemical compositions and kinematics of the Hercules stream". Monthly Notices of the Royal Astronomical Society. 460 (2): 1356−1370. arXiv:1604.04821. Bibcode:2016MNRAS.460.1356R. doi:10.1093/mnras/stw852.
- ^ Takeda, Yoichi; Tajitsu, Akito (2014). "Spectroscopic study on the beryllium abundances of red giant stars". Publications of the Astronomical Society of Japan. 66 (5): 91. arXiv:1406.7066. Bibcode:2014PASJ...66...91T. doi:10.1093/pasj/psu066.
- ^ Mason, B. D.; et al. (2014). "The Washington Visual Double Star Catalog". The Astronomical Journal. 122 (6): 3466. Bibcode:2001AJ....122.3466M. doi:10.1086/323920.