12 Cancri

From Wikipedia, the free encyclopedia
Jump to navigation Jump to search
12 Cancri
Observation data
Epoch J2000      Equinox J2000
Constellation Cancer
Right ascension  08h 08m 42.4457s[1]
Declination +13° 38′ 27.295″[1]
Apparent magnitude (V) 6.25[2]
Spectral type F3 V[3]
B−V color index 0.480±0.007[2]
Radial velocity (Rv)−10.0±4.3[4] km/s
Proper motion (μ) RA: +2.784[1] mas/yr
Dec.: −13.865[1] mas/yr
Parallax (π)12.50 ± 0.36[5] mas
Distance261 ± 8 ly
(80 ± 2 pc)
Absolute magnitude (MV)1.59[6]
Mass1.16[7] M
Luminosity17.94[2] L
Surface gravity (log g)3.60±0.14[7] cgs
Temperature6,357±88[8] K
Metallicity [Fe/H]0.04[8] dex
Rotational velocity (v sin i)52.3±4.1[6] km/s
Age2.466[7] Gyr
Other designations
12 Cnc, BD+14° 1831, HD 67483, HIP 39874, HR 3184, SAO 97594[9]
Database references

12 Cancri is a star in the zodiac constellation Cancer. It has an apparent visual magnitude of 6.25,[2] placing just below the normal limit for stars visible to the naked eye in good seeing conditions. The star displays an annual parallax shift of 12.50 mas as seen from Earth's orbit, which places it at a distance of about 261 light years. It is moving toward the Sun with a radial velocity of around −10 km/s.[4]

This is an ordinary F-type main-sequence star with a stellar classification of F3 V,[3] which indicates it is generating energy through hydrogen fusion at its core, it is spinning with a projected rotational velocity of 52[6] km/s and appears to be undergoing solar-like differential rotation with relative rate of α = 0.33±0.13.[10] The star is about 2.5[7] billion years old with 1.16[7] times the mass of the Sun and is radiating nearly 18[2] times the Sun's luminosity from its photosphere at an effective temperature of around 6,357 K.[8]


  1. ^ a b c d Gaia Collaboration; et al. (November 2016), "Gaia Data Release 1. Summary of the astrometric, photometric, and survey properties", Astronomy & Astrophysics, 595: 23, arXiv:1609.04172, Bibcode:2016A&A...595A...2G, doi:10.1051/0004-6361/201629512, A2.
  2. ^ a b c d e 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 Balachandran, Suchitra (May 1, 1990), "Lithium depletion and rotation in main-sequence stars", Astrophysical Journal, Part 1, 354: 310–332, Bibcode:1990ApJ...354..310B, doi:10.1086/168691.
  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. ^ 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.
  6. ^ a b c Ammler-von Eiff, M.; Reiners, A. (June 2012), "New measurements of rotation and differential rotation in A-F stars: are there two populations of differentially rotating stars?", Astronomy & Astrophysics, 542: A116, arXiv:1204.2459, Bibcode:2012A&A...542A.116A, doi:10.1051/0004-6361/201118724.
  7. ^ a b c d e 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.
  8. ^ a b c Casagrande, L.; et al. (June 2011), "New constraints on the chemical evolution of the solar neighbourhood and Galactic disc(s). Improved astrophysical parameters for the Geneva-Copenhagen Survey", Astronomy and Astrophysics, 530: A138, arXiv:1103.4651, Bibcode:2011A&A...530A.138C, doi:10.1051/0004-6361/201016276.
  9. ^ "12 Cnc". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2018-02-09.
  10. ^ Reiners, A.; Schmitt, J. H. M. M. (December 2003), "Differential rotation in rapidly rotating F-stars", Astronomy and Astrophysics, 412 (3): 813−819, arXiv:astro-ph/0309616, Bibcode:2003A&A...412..813R, doi:10.1051/0004-6361:20034255.