 A light curve for LU Comae Berenices, adapted from Henry et al. (2000). The plotted brightness is the average of the Strömgren b and y magnitudes. | |
| Observation data Epoch J2000.0 Equinox J2000.0 | |
|---|---|
| Constellation | Coma Berenices |
| Right ascension | 13 00 16.46725 |
| Declination | +30° 47′ 06.0644″ |
| Apparent magnitude (V) | 4.88 |
| Characteristics | |
| Evolutionary stage | Hertzsprung gap |
| Spectral type | G9 III CH-2 CN-1 |
| B−V color index | 1.165±0.014 |
| Variable type | RS CVn |
| Astrometry | |
| Radial velocity (Rv) | −14.34 km/s |
| Proper motion (μ) | RA: −18.662 mas/yr Dec.: −5.802 mas/yr |
| Parallax (π) | 4.6981 ± 0.2586 mas |
| Distance | 690 ± 40 ly (210 ± 10 pc) |
| Absolute magnitude (MV) | −1.62 |
| Details | |
| Mass | 5.25 M☉ |
| Radius | 38.2 R☉ |
| Luminosity (bolometric) | 590 L☉ |
| Surface gravity (log g) | 2.3 cgs |
| Temperature | 4,625 K |
| Metallicity | −0.05 dex |
| Rotation | 111 days |
| Rotational velocity (v sin i) | 11±1 km/s |
| Other designations | |
| 37 Com, 12 CVn, LU Com, BD+31°2434, HD 112989, HIP 63462, HR 4929, SAO 96265 | |
| Database references | |
| SIMBAD | data |
37 Comae Berenices is a variable star system located around 690 light years away from the Sun in the northern constellation of Coma Berenices. It has the variable star designation LU Comae Berenices. 37 Comae Berenices was a later Flamsteed designation of 13 Canum Venaticorum. This object is visible to the naked eye as a faint, yellow-hued star with a baseline apparent visual magnitude of 4.88. It is drifting closer to the Earth with a heliocentric radial velocity of −14 km/s.
Tokovinin (2008) catalogued this as a wide triple star system. The primary component is an aging giant star, currently in the Hertzsprung gap, with a stellar classification of G9 III CH-2 CN-1. It is a weak G-band star, a luminous giant star with a carbon abundance about a factor of 5 lower than is typical for such stars. This is a variable star most likely of the RS CVn type with an amplitude of 0.15 in magnitude, and it displays magnetic activity. It has 5.25 times the mass of the Sun and, having exhausted the supply of hydrogen at its core, has expanded to 38 times the Sun's radius.
References
- Henry, Gregory W.; Fekel, Francis C.; Henry, Stephen M.; Hall, Douglas S. (September 2000). "Photometric Variability in a Sample of 187 G and K Giants". The Astrophysical Journal Supplement Series. 130 (1): 201–225. Bibcode:2000ApJS..130..201H. doi:10.1086/317346. S2CID 17160805.
- ^ 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.
- ^ Aurière, M.; et al. (2015). "The magnetic fields at the surface of active single G-K giants". Astronomy & Astrophysics. 574: A90. arXiv:1411.6230. Bibcode:2015A&A...574A..90A. doi:10.1051/0004-6361/201424579. S2CID 118504829.
- ^ Tsvetkova, S.; et al. (March 2017). "Magnetic field structure in single late-type giants: The weak G-band giant 37 Comae from 2008 to 2011". Astronomy & Astrophysics. 599: 13. arXiv:1612.02669. Bibcode:2017A&A...599A..72T. doi:10.1051/0004-6361/201527034. S2CID 118944156. A72.
- ^ Keenan, Philip C.; McNeil, Raymond C. (1989), "The Perkins catalog of revised MK types for the cooler stars", Astrophysical Journal Supplement Series, 71: 245, Bibcode:1989ApJS...71..245K, doi:10.1086/191373.
- ^ 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.
- ^ Samus, N. N.; et al. (2017), "General Catalogue of Variable Stars", Astronomy Reports, GCVS 5.1, 61 (1): 80–88, Bibcode:2017ARep...61...80S, doi:10.1134/S1063772917010085, S2CID 125853869.
- ^ Famaey, B.; et al. (2005). "Local kinematics of K and M giants from CORAVEL/Hipparcos/Tycho-2 data. Revisiting the concept of superclusters". Astronomy and Astrophysics. 430: 165–186. arXiv:astro-ph/0409579. Bibcode:2005A&A...430..165F. doi:10.1051/0004-6361:20041272. S2CID 17804304.
- ^ "37 Com". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2019-07-16.
- Wagman, M. (August 1987). "Flamsteed's Missing Stars". Journal for the History of Astronomy. 18 (3): 214. Bibcode:1987JHA....18..209W. doi:10.1177/002182868701800305. S2CID 118445625.
- Lambert, D. L.; Ries, L. M. (Aug 15, 1981). "Carbon, nitrogen, and oxygen abundances in G and K giants". Astrophysical Journal. 248: 228–248. Bibcode:1981ApJ...248..228L. doi:10.1086/159147.
