Gamma Cancri

γ Cancri
Location of γ Cancri (circled)
Observation data
Epoch J2000.0      Equinox J2000.0 (ICRS)
Constellation Cancer
Right ascension 08h 43m 17.147s
Declination +21° 28′ 06.60″
Apparent magnitude (V) 4.673
Characteristics
Evolutionary stage main sequence
Spectral type A1IV
U−B color index +0.03
B−V color index +0.010
Astrometry
Radial velocity (Rv)28.7 km/s
Proper motion (μ) RA: −105.760 mas/yr
Dec.: −39.157 mas/yr
Parallax (π)18.6431±0.1900 mas
Distance175 ± 2 ly
(53.6 ± 0.5 pc)
Absolute magnitude (MV)+1.1
Details
Mass2.35±0.42 M☉
Radius2.53±0.23 R☉
Luminosity43.3±7.9 L☉
Surface gravity (log g)4.00±0.25 cgs
Temperature9,311 K
Rotational velocity (v sin i)86±6 km/s
Age171 Myr
Other designations
Asellus Borealis, γ Cnc, Gamma Cnc, 43 Cnc, BD+21°1895, FK5 1228, GC 11982, HD 74198, HIP 42806, HR 3449, SAO 80378, CCDM 08433+2128
Database references
SIMBADdata

Gamma Cancri is a star in the northern constellation of Cancer. Its name is a Bayer designation that is Latinized from γ Cancri, and abbreviated Gamma Cnc or γ Cnc. This star is formally named Asellus Borealis, pronounced /əˈsɛləs bɒriˈælɪs/, the traditional name of the system. Based on parallax measurements, it is located at a distance of approximately 175 light-years (54 pc) from the Sun. The star is drifting further away with a radial velocity of 29 km/s.

In 1910 this star was reported to be a spectroscopic binary by O. J. Lee, but is now considered a single star. Since it is near the ecliptic, it can be occulted by the Moon.

Nomenclature

γ Cancri (Latinised to Gamma Cancri) is the star's Bayer designation. It bore the traditional name Asellus Borealis (Latin for "northern donkey"). In 2016, the International Astronomical Union organized a Working Group on Star Names (WGSN) to catalogue and standardize proper names for stars. The WGSN decided to attribute proper names to individual stars rather than entire multiple systems. It approved the name Asellus Borealis for the star on 6 November 2016 and it is now so included in the List of IAU-approved Star Names. Together with Delta Cancri, it formed the Aselli, flanking Praesepe.

In Chinese astronomy, Ghost (Chinese: 鬼宿; pinyin: Guǐ Xiù) refers to an asterism consisting of Theta Cancri, Eta Cancri, Gamma Cancri and Delta Cancri. Gamma Cancri itself is known as the third star of Ghost (Chinese: 鬼宿三; pinyin: Guǐ Xiù sān).

Properties

Gamma Cancri presents as a white A-type subgiant with an apparent magnitude of +4.67. The star is an estimated 171 million years old and is spinning with a projected rotational velocity of 86 km/s. It has 2.35 times the mass of the Sun, 2.53 times the Sun's radius, and shines with a luminosity approximately 43 times greater at an effective temperature of 9,311 K.

It has been included as a member of the Hyades Stream based on its distance, space motion, and estimated age.

References

  1. 1 2 3 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.
  2. 1 2 3 4 5 Vallenari, A.; et al. (Gaia collaboration) (2023). "Gaia Data Release 3. Summary of the content and survey properties". Astronomy and Astrophysics. 674: A1. arXiv:2208.00211. Bibcode:2023A&A...674A...1G. doi:10.1051/0004-6361/202243940. S2CID 244398875. Gaia DR3 record for this source at VizieR.
  3. ↑ Zorec, J.; Royer, F. (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.
  4. 1 2 Abt, Helmut A.; Morrell, Nidia I. (1995). "The Relation between Rotational Velocities and Spectral Peculiarities among A-Type Stars". Astrophysical Journal Supplement. 95: 135. Bibcode:1995ApJS...99..135A. doi:10.1086/192182.
  5. ↑ Mermilliod, J.-C. (1986). "Compilation of Eggen's UBV data, transformed to UBV (unpublished)". Catalogue of Eggen's UBV Data. Bibcode:1986EgUBV........0M.
  6. 1 2 Wilson, Ralph Elmer (1953). "General catalogue of stellar radial velocities". Carnegie Institute Washington D.C. Publication. Bibcode:1953GCRV..C......0W.
  7. ↑ Eggen, O. J.; Iben, Icko Jr. (1988). "Starbursts, binary stars, and blue stragglers in local superclusters and groups. I - The very young disk and young disk populations". Astronomical Journal. 96: 635–669. Bibcode:1988AJ.....96..635E. doi:10.1086/114834.
  8. 1 2 3 4 5 6 Stassun, Keivan G.; et al. (2019). "The Revised TESS Input Catalog and Candidate Target List". The Astronomical Journal. 158 (4): 138. arXiv:1905.10694. Bibcode:2019AJ....158..138S. doi:10.3847/1538-3881/ab3467.
  9. 1 2 Royer, F.; et al. (2002). "Rotational velocities of A-type stars in the northern hemisphere. II. Measurement of v sin i". Astronomy and Astrophysics. 393 (3): 897–911. arXiv:astro-ph/0205255. Bibcode:2002A&A...393..897R. doi:10.1051/0004-6361:20020943. S2CID 14070763.
  10. 1 2 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. S2CID 33401607. Vizier catalog entry
  11. ↑ "gam Cnc". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 8 April 2015.
  12. 1 2 "Naming Stars". IAU.org. Archived from the original on 10 March 2025. Retrieved 16 December 2017.
  13. ↑ Lee, Oliver J. (November 1910). "Measures on nineteen new spectroscopic binaries". Astrophysical Journal. 32: 300–308. Bibcode:1910ApJ....32..300L. doi:10.1086/141806.
  14. ↑ Eggleton, P. P.; Tokovinin, A. A. (September 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.
  15. ↑ De Rosa, R. J.; et al. (July 2011). "The Volume-limited A-Star (VAST) survey - I. Companions and the unexpected X-ray detection of B6-A7 stars". Monthly Notices of the Royal Astronomical Society. 415 (1): 854–866. arXiv:1103.4363. Bibcode:2011MNRAS.415..854D. doi:10.1111/j.1365-2966.2011.18765.x. S2CID 84181878.
  16. ↑ Schmidtke, P. C.; Africano, J. L. (January 2011). "KPNO Lunar Occultation Summary. III". The Astronomical Journal. 141 (1): 7. Bibcode:2011AJ....141...10S. doi:10.1088/0004-6256/141/1/10. S2CID 120313180. 10.
  17. ↑ Dixon-Kennedy, Mike (1998), Encyclopedia of Greco-Roman Mythology, ABC-CLIO, p. 51, ISBN 9781576070949
  18. ↑ IAU Working Group on Star Names (WGSN), International Astronomical Union, archived from the original on 10 June 2016, retrieved 22 May 2016.
  19. ↑ "WG Triennial Report (2015-2018) - Star Names" (PDF). p. 5. Archived from the original (PDF) on 2019-08-23. Retrieved 2018-07-14.
  20. ↑ Allen, Richard H. (February 28, 2013). Star Names: Their Lore and Meaning. Courier Corporation. ISBN 978-0-486-13766-7.
  21. ↑ 陳久金 (2005). Zhōngguó Xīngzuò Shénhuà 中國星座神話 [Chinese Constellation Mythology]. 台灣古籍出版有限公司. p. 394. ISBN 978-986-7332-25-7.
  22. ↑ 亮星中英對照表 [English-Chinese Glossary of Bright Stars]. Hong Kong Space Museum (in Chinese). Retrieved February 3, 2018. Asellus Borealis
  23. ↑ Eggen, Olin J. (October 1992). "The Hyades Supercluster in FK5". Astronomical Journal. 104: 1482. Bibcode:1992AJ....104.1482E. doi:10.1086/116333.