57 Cancri
Star in the constellation Cancer
From Wikipedia, the free encyclopedia
57 Cancri is a double star in the zodiac constellation of Cancer, located around 460 light years away from the Sun.[1] They are visible to the naked eye as a faint star with a combined apparent visual magnitude of +5.40.[2] The brighter member, designated component A. is a yellow-hued giant star with a stellar classification of G7 III[4] and an apparent magnitude of +6.09.[3] Its companion, component B, is an orange-hued giant with a class of K0 III[4] and an apparent magnitude of +6.37.[3] As of 2017, the pair had an angular separation of 1.50″ along a position angle of 310°.[3] This angular separation translates to a projected separation of 180 astronomical units.[5]
| Observation data Epoch J2000.0 Equinox J2000.0 | |
|---|---|
| Constellation | Cancer |
| Right ascension | 08h 54m 14.73274s[1] |
| Declination | +30° 34′ 44.8283″[1] |
| Apparent magnitude (V) | +5.40[2] (6.09 + 6.37)[3] |
| Characteristics | |
| Spectral type | G7 III + K0 III[4] |
| B−V color index | 1.05[2] |
| Astrometry | |
| Radial velocity (Rv) | −57.68±0.28[5] km/s |
| Proper motion (μ) | RA: +41.60[1] mas/yr Dec.: −24.02[1] mas/yr |
| Parallax (π) | 7.07±0.68 mas[1] |
| Distance | 460 ± 40 ly (140 ± 10 pc) |
| Absolute magnitude (MV) | –0.33[2] |
| Details | |
| 57 Cnc A | |
| Mass | 2.80±0.04[5] M☉ |
| Luminosity | 173.13[2] L☉ |
| Surface gravity (log g) | 2.76+0.03 −0.04[5] cgs |
| Temperature | 5,269+272 −46[5] K |
| Metallicity [Fe/H] | 0.08±0.05[6] dex |
| Other designations | |
| 57 Cnc, BD+31°1907, GC 12289, HD 75959, HIP 43721, HR 3532, SAO 61125, ADS 7071, WDS J08542+3035[7] | |
| Database references | |
| SIMBAD | data |