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]
| 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) | −59.2±0.4[2] 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[5] | |
| 57 Cnc A | |
| Mass | 6.49±2.16 M☉ |
| Luminosity | 173.13[2] L☉ |
| Surface gravity (log g) | 2.74±0.11 cgs |
| Temperature | 4,810±92 K |
| Metallicity [Fe/H] | 0.08±0.05 dex |
| Age | 645+154 −120 Myr |
| Other designations | |
| Database references | |
| SIMBAD | data |
References
edit- ^ a b c d e f van Leeuwen, F. (2007), "Validation of the new Hipparcos reduction", Astronomy and Astrophysics, 474 (2): 653–664, arXiv:0708.1752, Bibcode:2007A&A...474..653V, doi:10.1051/0004-6361:20078357, S2CID 18759600.
- ^ a b c d e f Anderson, E.; Francis, Ch. (2012), "XHIP: An extended hipparcos compilation", Astronomy Letters, 38 (5): 331, arXiv:1108.4971, Bibcode:2012AstL...38..331A, doi:10.1134/S1063773712050015, S2CID 119257644.
- ^ a b c d Mason, B. D.; et al. (2014), "The Washington Visual Double Star Catalog", The Astronomical Journal, 122 (6): 3466, Bibcode:2001AJ....122.3466M, doi:10.1086/323920
- ^ a b c Abt, Helmut A. (2008), "Visual Multiples. IX. MK Spectral Types", The Astrophysical Journal Supplement Series, 176 (1): 216–217, Bibcode:2008ApJS..176..216A, doi:10.1086/525529.
- ^ Feuillet, Diane K.; et al. (2016), "Determining Ages of APOGEE Giants with Known Distances", The Astrophysical Journal, 817 (1): 40, arXiv:1511.04088, Bibcode:2016ApJ...817...40F, doi:10.3847/0004-637X/817/1/40, S2CID 118675933.
- ^ "57 Cnc". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2019-03-06.