57 Cancri

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	08^h 54^m 14.73274^s[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[1] mas
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
57 Cnc, BD+31°1907, GC 12289, HD 75959, HIP 43721, HR 3532, SAO 61125, ADS 7071, WDS J08542+3035[6]
Database references
SIMBAD	data

References

1. 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.
2. 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.
3. Mason, B. D.; et al. (2014), The Washington Visual Double Star Catalog, Bibcode:2001AJ....122.3466M, doi:10.1086/323920
4. Abt, Helmut A. (2008), "Visual Multiples. IX. MK Spectral Types", The Astrophysical Journal Supplement Series, 176: 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: 40, arXiv:1511.04088, Bibcode:2016ApJ...817...40F, doi:10.3847/0004-637X/817/1/40.
6. "57 Cnc". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2019-03-06.