27 Cancri

27 Cancri is a single[8] star in the zodiac constellation of Cancer, located around 990 light years away from the Sun.[1] It is visible to the naked eye as a faint, red-hued star with a typical apparent visual magnitude of around +5.56.[2] The star is moving closer to the Earth with a heliocentric radial velocity of −8.3 km/s.[5] It is a member of the Arcturus stream, a group of stars with high proper motion and metal-poor properties thought to be the remnants of a small galaxy consumed by the Milky Way.[9]

27 Cancri
Observation data
Epoch J2000.0      Equinox J2000.0
Constellation Cancer
Right ascension 08h 26m 43.94035s[1]
Declination +12° 39′ 16.6066″[1]
Apparent magnitude (V) +5.56[2]
Evolutionary stage Asymptotic giant branch[3]
Spectral type M3 IIIa[4]
B−V color index 1.608±0.002[2]
Variable type SRb[3]
Radial velocity (Rv)−8.30±0.31[5] km/s
Proper motion (μ) RA: −19.760[1] mas/yr
Dec.: −104.664[1] mas/yr
Parallax (π)3.3094 ± 0.3176[1] mas
Distance990 ± 90 ly
(300 ± 30 pc)
Absolute magnitude (MV)−1.62[2]
Radius119[1] R
[6] L
Surface gravity (log g)1.00[6] cgs
Temperature3,574[6] K
Metallicity [Fe/H]0.00[6] dex
Other designations
27 Cnc, BP Cancri, BD+13°1912, FK5 2658, GC 11525, HD 71250, HIP 41400, HR 3319, SAO 97819[7]
Database references

This is an aging red giant with a stellar classification of M3 IIIa,[4] currently on the asymptotic giant branch.[3] It is classified as a semiregular variable star of type SRb and its brightness varies from magnitude +5.41 to +5.75 with a period of 40 days.[10] The star is radiating around 2,455[6] times the Sun's luminosity from its enlarged photosphere at an effective temperature of 3,574 K.[6]


  1. ^ a b c d e f g 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 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, S2CID 119257644.
  3. ^ a b c Lebzelter, T.; Hron, J. (December 2003), "Technetium and the third dredge up in AGB stars. I. Field stars", Astronomy and Astrophysics, 411 (3): 533–542, arXiv:astro-ph/0310018, Bibcode:2003A&A...411..533L, doi:10.1051/0004-6361:20031458, S2CID 18879265.
  4. ^ a b Keenan, Philip C.; McNeil, Raymond C. (1989), "The Perkins catalog of revised MK types for the cooler stars", Astrophysical Journal Supplement Series, 71: 245, Bibcode:1989ApJS...71..245K, doi:10.1086/191373.
  5. ^ 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, S2CID 59451347, A61.
  6. ^ a b c d e f Maas, Z. G.; et al. (December 2016), "Chlorine Abundances in Cool Stars", The Astronomical Journal, 152 (6): 14, arXiv:1609.01626, Bibcode:2016AJ....152..196M, doi:10.3847/0004-6256/152/6/196, S2CID 118722950, 196.
  7. ^ "27 Cnc". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2019-02-26.
  8. ^ Eggleton, P. P.; Tokovinin, A. A. (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, S2CID 14878976.
  9. ^ Eggen, Olin (1971), "The Arcturus Group", Publications of the Astronomical Society of the Pacific, 83 (493): 271–85, Bibcode:1971PASP...83..271E, doi:10.1086/129120.
  10. ^ Samus, N. N.; et al. (2017), "General Catalogue of Variable Stars", Astronomy Reports, 5.1, 61 (1): 80–88, Bibcode:2017ARep...61...80S, doi:10.1134/S1063772917010085, S2CID 125853869.