27 Cancri is a single[1] star in the zodiac constellation of Cancer, located around 990 light-years away from the Sun.[2] It is visible to the naked eye as a faint, red-hued star with a typical apparent visual magnitude of around +5.5. The star is moving closer to the Earth with a heliocentric radial velocity of −8.3 km/s.[3] 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.[4]

The variability of the brightness of 27 Cancri was announced by Joel Stebbins and Charles Morse Huffer in 1928, based on observations made at Washburn Observatory.[5] It was given its variable star designation, BP Cancri, in 1977.[6]

This is an aging red giant with a stellar classification of M3 IIIa,[7] currently on the asymptotic giant branch.[8] 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.[9] The star is radiating around 2,455[10] times the Sun's luminosity from its enlarged photosphere at an effective temperature of 3,574 K.[10]

References

  1. ^ 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
  2. ^
  3. ^ 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
  4. ^ 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
  5. ^ Stebbins, Joel & Huffer, C. M. (1928). "The Constancy of the Light of Red Stars". Publications of the Washburn Observatory. 15: 137–174. Bibcode:1928PWasO..15..137S
  6. ^ Kukarkin, B. V.; Kholopov, P. N.; Kukarkina, N. P.; Perova, N. B. (October 1973). "59th Name-List of Variable Stars". Information Bulletin on Variable Stars. 834: 1–22. Bibcode:1973IBVS..834....1K. Retrieved 8 December 2024.
  7. ^ 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. S2CID 123149047
  8. ^ 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
  9. ^ Samus, N. N. et al. (2017), "General Catalogue of Variable Stars", Astronomy Reports. 61 (1): 80–88, 5.1, Bibcode:2017ARep...61...80S. doi:10.1134/S1063772917010085. S2CID 125853869
  10. ^ 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