50 Cancri

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50 Cancri
Observation data
Epoch J2000.0      Equinox J2000.0
Constellation Cancer
Right ascension  08h 46m 56.01919s[1]
Declination +12° 06′ 35.8305″[1]
Apparent magnitude (V) 5.89[2]
Evolutionary stage main sequence
Spectral type A1 Vp[3]
B−V color index 0.120±0.005[2]
Variable type None[4]
Radial velocity (Rv)23.3±2.9[2] km/s
Proper motion (μ) RA: −63.773[1] mas/yr
Dec.: −50.694[1] mas/yr
Parallax (π)17.7961 ± 0.0792[1] mas
Distance183.3 ± 0.8 ly
(56.2 ± 0.3 pc)
Absolute magnitude (MV)+1.82±0.01[4]
Mass2.1[5] M
Luminosity10.8±0.21[5] L
Surface gravity (log g)4.40[6] cgs
Temperature8,340±48[5] K
Rotational velocity (v sin i)18[7] km/s
Age264[6] Myr
Other designations
A2 Cancri, 50 Cnc, BD+12°1904, HD 74873, HIP 43121, HR 3481, SAO 98117[8]
Database references

50 Cancri is a single[9] star in the zodiac constellation of Cancer, located 183 light years away from the Sun.[1] It has the Bayer designation A2 Cancri; 50 Cancri is the Flamsteed designation. It is faintly visible to the naked eye as a white-hued star with an apparent visual magnitude of 5.89.[2] The star is moving away from the Earth with a heliocentric radial velocity of 23 km/s, having come to within 118 light-years some 1.2 million years ago.[2]

This is a chemically peculiar A-type main-sequence star with a stellar classification of A1 Vp,[3] it is a Lambda Boötis star displaying strongly-depleted iron peak and alpha process elements, but otherwise relatively normal solar abundances.[5] The star shows no variability down to a detection limit of 1.6 millimagnitudes.[10] It is 264[6] million years old with a relatively low projected rotational velocity of 18 km/s.[7] 50 Cancri has 2.1[5] times the mass of the Sun and is radiating 11[5] times the Sun's luminosity from its photosphere at an effective temperature of 8,340 K.[5]

50 Cancri has an infrared excess, which most likely indicates a debris disk in orbit around the host star. A blackbody model of the emission shows a two component fit, with the warm section having a temperature of 246±91 K at a radius of 4±AU from the star, and a cool component at 108±21 K with a separation of 22±8 AU.[5]


  1. ^ a b c d e f Brown, A. G. A.; et al. (Gaia collaboration) (August 2018). "Gaia Data Release 2: Summary of the contents and survey properties". Astronomy & Astrophysics. 616. A1. arXiv:1804.09365. Bibcode:2018A&A...616A...1G. doi:10.1051/0004-6361/201833051. Gaia DR2 record for this source at VizieR.
  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 Abt, Helmut A.; Morrell, Nidia I. (1995), "The Relation between Rotational Velocities and Spectral Peculiarities among A-Type Stars", Astrophysical Journal Supplement, 99: 135, Bibcode:1995ApJS...99..135A, doi:10.1086/192182.
  4. ^ a b Paunzen, E.; et al. (November 2002), "The status of Galactic field λ Bootis stars in the post-Hipparcos era", Monthly Notices of the Royal Astronomical Society, 336 (3): 1030–1042, arXiv:astro-ph/0207488, Bibcode:2002MNRAS.336.1030P, doi:10.1046/j.1365-8711.2002.05865.x.
  5. ^ a b c d e f g h Draper, Z. H.; et al. (2016), "IR excesses around nearby Lambda Boo stars are caused by debris discs rather than ISM bow waves", Monthly Notices of the Royal Astronomical Society, 456 (1): 459, Bibcode:2016MNRAS.456..459D.
  6. ^ a b c 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.
  7. ^ a b Zorec, J.; et al. (2012), "Rotational velocities of A-type stars. IV. Evolution of rotational velocities", Astronomy and Astrophysics, 537: A120, arXiv:1201.2052, Bibcode:2012A&A...537A.120Z, doi:10.1051/0004-6361/201117691.
  8. ^ "50 Cnc". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2019-03-06.
  9. ^ De Rosa, R. J.; et al. (2014), "The VAST Survey - III. The multiplicity of A-type stars within 75 pc", Monthly Notices of the Royal Astronomical Society, 437 (2): 1216, arXiv:1311.7141, Bibcode:2014MNRAS.437.1216D, doi:10.1093/mnras/stt1932.
  10. ^ Paunzen, E.; et al. (September 2002), "On the Period-Luminosity-Colour-Metallicity relation and the pulsational characteristics of lambda Bootis type stars", Astronomy and Astrophysics, 392: 515–528, arXiv:astro-ph/0207494, Bibcode:2002A&A...392..515P, doi:10.1051/0004-6361:20020854.