Alpha Comae Berenices
| Observation data Epoch J2000.0 Equinox J2000.0 (ICRS) | |
|---|---|
| Constellation | Coma Berenices |
| Right ascension | 13h 09m 59.285s |
| Declination | +17° 31′ 46.04″ |
| Apparent magnitude (V) | 4.29 to 4.35 (combined) A: 4.85 / B: 5.53 |
| Characteristics | |
| Spectral type | A: F5V / B: F5V (binary star) |
| U−B color index | −0.06 |
| B−V color index | 0.45 |
| V−R color index | 0.2 |
| R−I color index | 0.2 |
| Astrometry | |
| Radial velocity (Rv) | −17.7±0.9 km/s |
| Proper motion (μ) | RA: −433.13±0.70 mas/yr Dec.: 141.24±0.51 mas/yr |
| Parallax (π) | 56.10±0.89 mas |
| Distance | 58.1 ± 0.9 ly (17.8 ± 0.3 pc) |
| Absolute magnitude (MV) | 3.82 |
| Orbit | |
| Period (P) | 25.8696±0.008219 yr |
| Semi-major axis (a) | 0.67144±0.00033″ |
| Eccentricity (e) | 0.51060±0.00061 |
| Inclination (i) | 90.0501±0.0062° |
| Longitude of the node (Ω) | 12.2272±0.0098° |
| Periastron epoch (T) | 57056.84±0.36 |
| Argument of periastron (ω) (secondary) | 100.563±0.026° |
| Details | |
| A | |
| Mass | 1.237 M☉ |
| Luminosity | 1.72 L☉ |
| Surface gravity (log g) | 4.19 cgs |
| Temperature | 6,365 K |
| Metallicity [Fe/H] | −0.23 dex |
| B | |
| Mass | 1.087 M☉ |
| Luminosity | 1.75 L☉ |
| Temperature | 6,378 K |
| Other designations | |
| α Com, Alpha Comae Berenices, Alpha Com, 42 Comae Berenices, 42 Com, STF 1728, ADS 8804 , BD+18 2697, CCDM J13100+1732, GC 17833, Gliese 501, HIP 64241, IDS 13051+1803 AB, LTT 13802, NLTT 33105, PPM 129630, SAO 100443, WDS 13100+1732. | |
| A: HD 114378, HR 4968 | |
| B: HD 114379, HR 4969 | |
| Database references | |
| SIMBAD | data |
Alpha Comae Berenices (α Comae Berenices, abbreviated Alpha Com, α Com) is a binary star in the constellation of Coma Berenices (Berenice's Hair), 17.8 parsecs (58 ly) away. It consists of two main sequence stars, each a little hotter and more luminous than the Sun.
Alpha Comae Berenices is said to represent the crown worn by Queen Berenice. The two components are designated Alpha Comae Berenices A (officially named Diadem /ˈdaɪədɛm/, the traditional name for the system) and B.