37 Comae Berenices
Triple-star system in the constellation Coma Berenices
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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 â14 km/s.[8]
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 Epoch J2000.0 Equinox J2000.0 | |
|---|---|
| Constellation | Coma Berenices[2] |
| Right ascension | 13h 00m 16.46725s[3] |
| Declination | +30° 47â² 06.0644â³[3] |
| Apparent magnitude (V) | 4.88[4] |
| Characteristics | |
| Evolutionary stage | subgiant[5] |
| Spectral type | G9 III CH-2 CN-1[6] |
| BâV color index | 1.165±0.014[2] |
| Variable type | RS CVn[7] |
| Astrometry | |
| Radial velocity (Rv) | â14.34[8] km/s |
| Proper motion (μ) | RA: â18.662[3] mas/yr Dec.: â5.802[3] mas/yr |
| Parallax (Ï) | 4.6981±0.2586 mas[3] |
| Distance | 690 ± 40 ly (210 ± 10 pc) |
| Absolute magnitude (MV) | â1.62[2] |
| Details[4] | |
| Mass | 5.25 Mâ |
| Radius | 38.2 Râ |
| Luminosity (bolometric) | 590 Lâ |
| Surface gravity (log g) | 2.3 cgs |
| Temperature | 4,625[5] K |
| Metallicity [Fe/H] | â0.05[5] dex |
| Rotation | 111 days[5] |
| Rotational velocity (v sin i) | 11±1[5] km/s |
| Other designations | |
| 37 Com, 13 CVn, LU Com, BD+31°2434, HD 112989, HIP 63462, HR 4929, SAO 96265[9] | |
| Database references | |
| SIMBAD | data |
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]