Gamma Comae Berenices
Star in the constellation Coma Berenices
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Gamma Comae Berenices, Latinized from γ Comae Berenices, is a single,[11] orange-hued star in the northern constellation of Coma Berenices. It is faintly visible to the naked eye, having an apparent visual magnitude of 4.36.[2] Based upon an annual parallax shift of 19.50 mas as seen from Earth, its distance can be estimated as around 167 light years from the Sun. The star is moving away from the Sun with a radial velocity of +3 km/s.[5]
 | |
| Observation data Epoch J2000.0 Equinox J2000.0 (ICRS) | |
|---|---|
| Constellation | Coma Berenices |
| Right ascension | 12h 26m 56.27207s[1] |
| Declination | +28° 16â² 06.3211â³[1] |
| Apparent magnitude (V) | 4.36[2] |
| Characteristics | |
| Spectral type | K1 III Fe0.5[3] |
| UâB color index | +1.16[2] |
| BâV color index | +1.13[2] |
| RâI color index | +0.51[4] |
| Astrometry | |
| Radial velocity (Rv) | +3.38±0.11[5] km/s |
| Proper motion (μ) | RA: â83.990 ± 0.418[6] mas/yr Dec.: â82.216 ± 0.345[6] mas/yr |
| Parallax (Ï) | 19.2552±0.2371 mas[6] |
| Distance | 169 ± 2 ly (51.9 ± 0.6 pc) |
| Absolute magnitude (MV) | 0.76[7] |
| Details[8] | |
| Mass | 1.65±0.18 Mâ |
| Radius | 12.01+0.36 â0.34[9] Râ |
| Luminosity | 61.4±3.3[9] Lâ |
| Surface gravity (log g) | 2.53±0.05 cgs |
| Temperature | 4,660±84[9] K |
| Metallicity [Fe/H] | 0.16±0.10 dex |
| Rotational velocity (v sin i) | ⤠17[4] km/s |
| Age | 2.72±0.78 Gyr |
| Other designations | |
| γ Com, 15 Comae Berenices, BD+29°2288, FK5 2999, GC 16964, HD 108381, HIP 60742, HR 4737, SAO 82313, PPM 101903[10] | |
| Database references | |
| SIMBAD | data |
This is an evolved K-type giant star with a stellar classification of K1 III Fe0.5.[3] The suffix notation indicates the star displays an overabundance of iron in its spectrum. It is most likely (91% chance) on the horizontal branch with an age of 2.7 billion years. If this is true, then it has an estimated 1.65 times the mass of the Sun and has expanded to nearly 12 times the Sun's radius. The star is radiating 58 times the Sun's luminosity from its enlarged photosphere at an effective temperature of around 4,652 K.[8] Gamma Comae Berenices appears as part of the Coma Star Cluster, although it is probably not actually a member of this cluster.[12]
R. H. Allen's Star Names attributes the name Al á¸afÄ«rah to this star, from an Arabic name for the Coma Star Cluster.[13] In Chinese astronomy, it is identified as LángwèiyÄ« (éä½ä¸), meaning it is the first star of the asterism Lángwèi (éä½, Officers of the Imperial Guard).[14][15]