37 Comae Berenices
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 | 13h 00m 16.46725s |
| 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 [Fe/H] | −0.05 dex |
| Rotation | 111 days |
| Rotational velocity (v sin i) | 11±1 km/s |
| Other designations | |
| 37 Com, 13 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. José Renan De Medeiros et al. announced that the star is a variable star, in 1999. It was given its variable star designation in 2003. 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.