Astronomy:37 Comae Berenices
250px A light curve for LU Comae Berenices, adapted from Henry et al. (2000).[1] The plotted brightness is the average of the Strömgren b and y magnitudes. | |
| Observation data Equinox J2000.0]] (ICRS) | |
|---|---|
| Constellation | Coma Berenices[2] |
| Right ascension | 13h 00m 16.46725s[3] |
| Declination | +30° 47′ 06.0644″[3] |
| Apparent magnitude (V) | 4.88[4] |
| Characteristics | |
| Evolutionary stage | Hertzsprung gap[5] |
| Spectral type | G9 III CH-2 CN-1[6] |
| B−V color index | 1.165±0.014[2] |
| Variable type | RS CVn[7] |
| Astrometry | |
| Radial velocity (Rv) | −14.34[8] km/s |
| Proper motion (μ) | RA: −18.662[3] mas/yr Dec.: −5.802[3] mas/yr |
| Parallax (π) | 4.6981 ± 0.2586[3] mas |
| Distance | 690 ± 40 ly (210 ± 10 pc) |
| Absolute magnitude (MV) | −1.62[2] |
| Details[4] | |
| Mass | 5.25 M☉ |
| Radius | 38.2 R☉ |
| Luminosity (bolometric) | 590 L☉ |
| Surface gravity (log g) | 2.3 cgs |
| Temperature | 4,625[5] K |
| Metallicity [Fe/H] | −0.05[5] dex |
| Rotation | 111 days[5] |
| Rotational velocity (v sin i) | 11±1[5] km/s |
| Other designations | |
| Database references | |
| SIMBAD | data |
37 Comae Berenices is a variable star system located around 690[3] light years away from the Sun in the northern constellation of Coma Berenices.[9] It has the variable star designation LU Comae Berenices. 37 Comae Berenices was a later Flamsteed designation of 13 Canum Venaticorum.[10] This object is visible to the naked eye as a faint, yellow-hued star with a baseline apparent visual magnitude of 4.88.[4] It is drifting closer to the Earth with a heliocentric radial velocity of −14 km/s.[8]
Tokovinin (2008) catalogued this as a wide triple star system.[5] The primary component is an aging giant star, currently in the Hertzsprung gap,[5] with a stellar classification of G9 III CH-2 CN-1.[6] It is a weak G-band star,[5] a luminous giant star with a carbon abundance about a factor of 5 lower than is typical for such stars.[11] José Renan De Medeiros et al. announced that the star is a variable star, in 1999.[12] It was given its variable star designation in 2003.[13] This is a variable star most likely of the RS CVn type with an amplitude of 0.15 in magnitude,[7] and it displays magnetic activity.[5] 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.[4]
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. doi:10.1086/317346. Bibcode: 2000ApJS..130..201H.
- ↑ 2.0 2.1 2.2 Anderson, E.; Francis, Ch. (2012). "XHIP: An extended hipparcos compilation". Astronomy Letters 38 (5): 331. doi:10.1134/S1063773712050015. Bibcode: 2012AstL...38..331A XHIP record for this object at VizieR.
- ↑ 3.0 3.1 3.2 3.3 3.4 3.5 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. Gaia DR2 record for this source at VizieR.
- ↑ 4.0 4.1 4.2 4.3 Aurière, M. et al. (2015). "The magnetic fields at the surface of active single G-K giants". Astronomy & Astrophysics 574: A90. doi:10.1051/0004-6361/201424579. Bibcode: 2015A&A...574A..90A.
- ↑ 5.0 5.1 5.2 5.3 5.4 5.5 5.6 5.7 5.8 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. doi:10.1051/0004-6361/201527034. A72. Bibcode: 2017A&A...599A..72T.
- ↑ 6.0 6.1 Keenan, Philip C.; McNeil, Raymond C. (1989). "The Perkins catalog of revised MK types for the cooler stars". Astrophysical Journal Supplement Series 71: 245. doi:10.1086/191373. Bibcode: 1989ApJS...71..245K.
- ↑ 7.0 7.1 Samus, N. N. et al. (2017). "General Catalogue of Variable Stars". Astronomy Reports. GCVS 5.1 61 (1): 80–88. doi:10.1134/S1063772917010085. Bibcode: 2017ARep...61...80S.
- ↑ 8.0 8.1 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. doi:10.1051/0004-6361:20041272. Bibcode: 2005A&A...430..165F.
- ↑ 9.0 9.1 "37 Com". SIMBAD. Centre de données astronomiques de Strasbourg. http://simbad.u-strasbg.fr/simbad/sim-basic?Ident=37+Com.
- ↑ Wagman, M. (August 1987). "Flamsteed's Missing Stars". Journal for the History of Astronomy 18 (3): 214. doi:10.1177/002182868701800305. Bibcode: 1987JHA....18..209W.
- ↑ Lambert, D. L.; Ries, L. M. (Aug 15, 1981). "Carbon, nitrogen, and oxygen abundances in G and K giants". Astrophysical Journal 248: 228–248. doi:10.1086/159147. Bibcode: 1981ApJ...248..228L.
- ↑ de Medeiros, J. R.; Konstantinova-Antova, R. K.; da Silva, J. R. P. (July 1999). "The peculiar single giant HD 112989: rotation, activity and evolution". Astronomy and Astrophysics 347: 550–555. Bibcode: 1999A&A...347..550D.
- ↑ Kazarovets, E. V.; Kireeva, N. N.; Samus, N. N.; Durlevich, O. V. (May 2003). "The 77th Name-List of Variable Stars". Information Bulletin on Variable Stars 5422: 1–56. Bibcode: 2003IBVS.5422....1K.
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