54 Cancri

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54 Cancri
Observation data
Epoch J2000      Equinox J2000
Constellation Cancer
Right ascension  08h 51m 01.4644s[1]
Declination +15° 21′ 02.364″[1]
Apparent magnitude (V) 6.38[2]
Spectral type G5 V[3]
B−V color index 0.629±0.020[2]
Radial velocity (Rv)+45.098±0.032[2] km/s
Proper motion (μ) RA: −112.475[1] mas/yr
Dec.: +75.099[1] mas/yr
Parallax (π)24.79 ± 0.33[1] mas
Distance132 ± 2 ly
(40.3 ± 0.5 pc)
Absolute magnitude (MV)3.39[2]
Mass1.23±0.05 M
Radius1.81±0.20 R
Surface gravity (log g)4.04±0.04 cgs
Temperature5,862±15 K
Rotational velocity (v sin i)3.10±0.56 km/s
Other designations
54 Cnc, BD+15° 1917, FK5 2699, HD 75528, HIP 43454, HR 3510, SAO 98168[4]
Database references

54 Cancri is a star in the zodiac constellation of Cancer. It has an apparent visual magnitude of 6.38,[2] which places it just below the normal brightness limit of stars visible to the naked eye. The annual parallax shift is 24.79 mas as measured from Earth's orbit, which yields a distance estimate of about 132 light years. It is moving away from the Sun with a radial velocity of +45 km/s.[2]

Measurement of the stars proper motion over time suggest changes due to an acceleration component, which may indicate it is a close binary system;[5] the visible component has a stellar classification of G5 V,[3] indicating it is an ordinary G-type main-sequence star that is generating energy through hydrogen fusion in its core region. Hall et al. (2007) classify it as a low-activity variable star.[3] The star is about five billion years old with a projected rotational velocity of 3.1 km/s. It has 1.23 times the mass of the Sun and 1.81 times the Sun's radius.[2]


  1. ^ a b c d e 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 f g h Niedzielski, A.; et al. (January 2016), "The Penn State - Toruń Centre for Astronomy Planet Search stars", Astronomy & Astrophysics, 585: 14, arXiv:1407.4956, Bibcode:2016A&A...585A..73N, doi:10.1051/0004-6361/201527362, A73.
  3. ^ a b c Hall, Jeffrey C.; et al. (March 2007), "The Activity and Variability of the Sun and Sun-like Stars. I. Synoptic Ca II H and K Observations", The Astronomical Journal, 133 (3): 862–881, Bibcode:2007AJ....133..862H, doi:10.1086/510356.
  4. ^ "54 Cnc". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2018-02-09.
  5. ^ Mason, Brian D.; et al. (1999), "Speckle Interferometry of New and Problem HIPPARCOS Binaries", The Astronomical Journal, 117 (4): 1890−1904, Bibcode:1999AJ....117.1890M, doi:10.1086/300823.