8 Cancri

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8 Cancri
Observation data
Epoch J2000      Equinox J2000
Constellation Cancer
Right ascension  08h 05m 04.48834s[1]
Declination +13° 07′ 05.5757″[1]
Apparent magnitude (V) +5.14[2]
Spectral type A1 V[3]
B−V color index 0.018±0.005[2]
Radial velocity (Rv)+21.0±4.2[4] km/s
Proper motion (μ) RA: −35.78[1] mas/yr
Dec.: −63.81[1] mas/yr
Parallax (π)15.20 ± 0.32[1] mas
Distance215 ± 5 ly
(66 ± 1 pc)
Absolute magnitude (MV)1.05[2]
Mass2.37[5] M
Luminosity36.6[2] L
Surface gravity (log g)4.29±0.14[5] cgs
Temperature10,352±352[5] K
Rotational velocity (v sin i)173[5] km/s
Age144[5] Myr
Other designations
8 Cnc, BD+13° 1831, FK5 2625, GC 10959, HD 66664, HIP 39567, HR 3163, SAO 97542[6]
Database references

8 Cancri is a single,[7] white-hued star in the zodiac constellation of Cancer. It has an apparent visual magnitude of +5.14,[2] which indicates it is faintly visible to the naked eye under suitable viewing conditions. The distance to this star, as determined from its annual parallax shift of 15.20 mas,[1] is around 215 light years. A radial velocity of +21 km/s indicates it is moving away from the Sun.[4]

This is an A-type main-sequence star with a stellar classification of A1 V,[3] it is a young star with an estimated age of just 144[5] million years, and has a high rate of spin with a projected rotational velocity of 173 km/s.[5] 8 Cancri has 2.37[5] times the mass of the Sun and is radiating 36.6[2] times the Sun's luminosity from its photosphere at an effective temperature of around 10,352 K.[5]


  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.
  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.
  3. ^ a b Cowley, A.; et al. (April 1969), "A study of the bright A stars. I. A catalogue of spectral classifications", Astronomical Journal, 74: 375–406, Bibcode:1969AJ.....74..375C, doi:10.1086/110819.
  4. ^ a b de Bruijne, J. H. J.; Eilers, A.-C. (October 2012), "Radial velocities for the HIPPARCOS-Gaia Hundred-Thousand-Proper-Motion project", Astronomy & Astrophysics, 546: 14, arXiv:1208.3048, Bibcode:2012A&A...546A..61D, doi:10.1051/0004-6361/201219219, A61.
  5. ^ a b c d e f g h i David, Trevor J.; Hillenbrand, Lynne A. (2015), "The Ages of Early-type Stars: Strömgren Photometric Methods Calibrated, Validated, Tested, and Applied to Hosts and Prospective Hosts of Directly Imaged Exoplanets", The Astrophysical Journal, 804 (2): 146, arXiv:1501.03154, Bibcode:2015ApJ...804..146D, doi:10.1088/0004-637X/804/2/146.
  6. ^ "8 Cnc". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2018-02-09.
  7. ^ Eggleton, P. P.; Tokovinin, A. A. (September 2008), "A catalogue of multiplicity among bright stellar systems", Monthly Notices of the Royal Astronomical Society, 389 (2): 869–879, arXiv:0806.2878, Bibcode:2008MNRAS.389..869E, doi:10.1111/j.1365-2966.2008.13596.x.