28 Monocerotis is a single[12] star in the equatorial constellation of Monoceros. It has an orange-hue and is faintly visible to the naked eye with an apparent visual magnitude of 4.69.[3] The distance to this star is approximately 450 light years based on parallax,[2] and it has an absolute magnitude of −1.00.[3] The star is drifting further away from the Sun with a radial velocity of +26.7 km/s.[6]
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Monoceros |
| Right ascension | 08h 01m 13.33574s[2] |
| Declination | −01° 23′ 33.3935″[2] |
| Apparent magnitude (V) | 4.69[3] |
| Characteristics | |
| Spectral type | K4III[4] |
| U−B color index | +1.76[5] |
| B−V color index | +1.49[5] |
| Astrometry | |
| Radial velocity (Rv) | +26.70[6] km/s |
| Proper motion (μ) | RA: +67.60[2] mas/yr Dec.: −76.26[2] mas/yr |
| Parallax (π) | 7.25 ± 0.30 mas[2] |
| Distance | 450 ± 20 ly (138 ± 6 pc) |
| Absolute magnitude (MV) | −1.00[3] |
| Details | |
| Mass | 2.193±0.110[7] M☉ |
| Radius | 47.69+0.46 −2.21[8] R☉ |
| Luminosity | 524±42[8] L☉ |
| Surface gravity (log g) | 1.68[9] cgs |
| Temperature | 3,999+96 −19[8] K |
| Metallicity [Fe/H] | −0.26[3] dex |
| Rotational velocity (v sin i) | 2.2[10] km/s |
| Other designations | |
| Database references | |
| SIMBAD | data |
This is an aging giant star with a stellar classification of K4III,[4] having exhausted the supply of hydrogen at its core then cooled and expanded off the main sequence. The spectrum of the star shows abnormally strong lines of CN.[13] It is classified as an FK Comae Berenices variable, varying by 0.02 magnitude over a period of 0.21 days.[14][1] FK Comae Berenices variables are typically rapidly-rotating stars, but the measured projected rotational velocity of 28 Monocerotis is low.[10] The star has expanded to 48 times the radius of the Sun. It is radiating 524 times the Sun's luminosity from its enlarged photosphere at an effective temperature of 3,999 K.[8]
Measurement of the star's proper motion anomaly by the Gaia spacecraft suggests a companion may be orbiting the star at a distance of 1.9 AU.[7]
References
edit- ^ a b Stift, M. J. (January 1979). "5-hour Light Variation of HD 65953 (28 Mon)?". Information Bulletin on Variable Stars. 1542: 1. Bibcode:1979IBVS.1542....1S.
- ^ a b c d e f Van Leeuwen, F. (2007). "Validation of the new Hipparcos reduction". Astronomy and Astrophysics. 474 (2): 653–664. arXiv:0708.1752. Bibcode:2007A&A...474..653V. doi:10.1051/0004-6361:20078357. S2CID 18759600. Vizier catalog entry
- ^ a b c d e 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
- ^ a b Houk, N.; Swift, C. (1999). "Michigan catalogue of two-dimensional spectral types for the HD Stars". Michigan Spectral Survey. 5. Bibcode:1999MSS...C05....0H.
- ^ a b Mermilliod, J. C. (2006). "VizieR Online Data Catalog: Homogeneous Means in the UBV System (Mermilliod 1991)". VizieR On-line Data Catalog: II/168. Originally Published in: Institut d'Astronomie. 2168. Bibcode:2006yCat.2168....0M.Vizier catalog entry
- ^ a b Gontcharov, G. A. (2006). "Pulkovo Compilation of Radial Velocities for 35 495 Hipparcos stars in a common system". Astronomy Letters. 32 (11): 759–771. arXiv:1606.08053. Bibcode:2006AstL...32..759G. doi:10.1134/S1063773706110065. S2CID 119231169.
- ^ a b Kervella, Pierre; et al. (March 2019). "Stellar and substellar companions of nearby stars from Gaia DR2. Binarity from proper motion anomaly". Astronomy & Astrophysics. 623: 23. arXiv:1811.08902. Bibcode:2019A&A...623A..72K. doi:10.1051/0004-6361/201834371. S2CID 119491061. A72.
- ^ a b c d 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.
- ^ Soubiran, Caroline; Le Campion, Jean-François; Brouillet, Nathalie; Chemin, Laurent (2016). "The PASTEL catalogue: 2016 version". Astronomy & Astrophysics. 591: A118. arXiv:1605.07384. Bibcode:2016A&A...591A.118S. doi:10.1051/0004-6361/201628497. S2CID 119258214.
- ^ a b De Medeiros, J. R.; Alves, S.; Udry, S.; Andersen, J.; Nordström, B.; Mayor, M. (2014). "A catalog of rotational and radial velocities for evolved stars". Astronomy & Astrophysics. 561: A126. arXiv:1312.3474. Bibcode:2014A&A...561A.126D. doi:10.1051/0004-6361/201220762. S2CID 54046583. Vizier catalog entry
- ^ "28 Mon". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2020-10-20.
- ^ Eggleton, P. P.; Tokovinin, A. A. (September 2008). "A catalogue of multiplicity among bright stellar systems". Monthly Notices of the Royal Astronomical Society. 389 (2): 869–879. arXiv:0806.2878. Bibcode:2008MNRAS.389..869E. doi:10.1111/j.1365-2966.2008.13596.x. S2CID 14878976.
- ^ Eggen, Olin J. (October 1996). "Star Streams and Galactic Structure". Astronomical Journal. 112: 1595. Bibcode:1996AJ....112.1595E. doi:10.1086/118126.
- ^ Samus, N. N.; Durlevich, O. V.; et al. (2009). "VizieR Online Data Catalog: General Catalogue of Variable Stars (Samus+ 2007-2013)". VizieR On-line Data Catalog: B/GCVS. Originally Published in: 2009yCat....102025S. 1. Bibcode:2009yCat....102025S.