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]

57 Cancri
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]
Distance460 ± 40 ly
(140 ± 10 pc)
Absolute magnitude (MV)–0.33[2]
Details[5]
57 Cnc A
Mass6.49±2.16 M
Luminosity173.13[2] L
Surface gravity (log g)2.74±0.11 cgs
Temperature4,810±92 K
Metallicity [Fe/H]0.08±0.05 dex
Age645+154
−120
 Myr
Other designations
57 Cnc, BD+31°1907, GC 12289, HD 75959, HIP 43721, HR 3532, SAO 61125, ADS 7071, WDS J08542+3035[6]
Database references
SIMBADdata

References

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  1. ^ 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.
  2. ^ 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.
  3. ^ 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
  4. ^ 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.
  5. ^ 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.
  6. ^ "57 Cnc". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2019-03-06.