27 Monocerotis
27 Monocerotis is a single[8] star located about 318[1] light years away from the Sun star in the equatorial constellation of Monoceros. It is visible to the naked eye as a faint, orange-hued star with an apparent visual magnitude of 4.93.[2] The star is advancing toward the Earth with a heliocentric radial velocity of −28 km/s.[5]
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Monoceros |
| Right ascension | 07h 59m 44.15308s[1] |
| Declination | −3° 40′ 46.5065″[1] |
| Apparent magnitude (V) | 4.93[2] |
| Characteristics | |
| Spectral type | K2III[3] |
| U−B color index | +1.21[4] |
| B−V color index | +1.21[4] |
| Astrometry | |
| Radial velocity (Rv) | −28.02[5] km/s |
| Proper motion (μ) | RA: −54.379[1] mas/yr Dec.: −3.132[1] mas/yr |
| Parallax (π) | 10.2424 ± 0.1791 mas[1] |
| Distance | 318 ± 6 ly (98 ± 2 pc) |
| Absolute magnitude (MV) | 0.30[2] |
| Details[6] | |
| Mass | 1.28±0.20 M☉ |
| Radius | 13.41±1.11 R☉ |
| Luminosity | 148.283[1] L☉ |
| Surface gravity (log g) | 2.40±0.04 cgs |
| Temperature | 4,568±12 K |
| Metallicity [Fe/H] | −0.25±0.03 dex |
| Rotational velocity (v sin i) | 1.76±0.56 km/s |
| Age | 3.87±1.86 Gyr |
| Other designations | |
| Database references | |
| SIMBAD | data |
This object is an aging giant star, most likely (94% chance) on the red giant branch,[9] with a stellar classification of K2III.[3] Having exhausted the hydrogen at its core, the star has evolved off the main sequence and expanded to over 13 times the girth of the Sun. It is around four billion years old with 1.3 times the Sun's mass.[6] The star is radiating 148[1] times the Sun's luminosity from its swollen photosphere at an effective temperature of 4,568 K.[6]
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.
- 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. Vizier catalog entry
- Hoffleit, D.; Warren, W. H. (1995). "VizieR Online Data Catalog: Bright Star Catalogue, 5th Revised Ed. (Hoffleit+, 1991)". VizieR On-line Data Catalog: V/50. Originally Published in: 1964BS....C......0H. 5050. Bibcode:1995yCat.5050....0H.
- Mallama, A. (2014). "Sloan Magnitudes for the Brightest Stars". The Journal of the American Association of Variable Star Observers. 42 (2): 443. Bibcode:2014JAVSO..42..443M.Vizier catalog entry
- Jofré, E.; Petrucci, R.; Saffe, C.; Saker, L.; Artur de la Villarmois, E.; Chavero, C.; Gómez, M.; Mauas, P. J. D. (2015). "Stellar parameters and chemical abundances of 223 evolved stars with and without planets". Astronomy & Astrophysics. 574: A50. arXiv:1410.6422. Bibcode:2015A&A...574A..50J. doi:10.1051/0004-6361/201424474. S2CID 53666931. Vizier catalog entry
- Jofré, E.; et al. (2015). "Stellar parameters and chemical abundances of 223 evolved stars with and without planets". Astronomy and Astrophysics. 574: A50. arXiv:1410.6422. Bibcode:2015A&A...574A..50J. doi:10.1051/0004-6361/201424474. S2CID 53666931.
- "20 Mon". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2019-05-31.
- 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.
- Stock, S.; Reffert, S.; Quirrenbach, A. (August 2018). "Precise radial velocities of giant stars. X. Bayesian stellar parameters and evolutionary stages for 372 giant stars from the Lick planet search". Astronomy & Astrophysics. 616: 15. arXiv:1805.04094. Bibcode:2018A&A...616A..33S. doi:10.1051/0004-6361/201833111. S2CID 119361866. A33.