Γ_Cancri

Gamma Cancri

Gamma Cancri

Star system in the constellation Cancer

Gamma Cancri, or γ Cancri, is a star in the northern constellation of Cancer. It is formally named Asellus Borealis /əˈsɛləs bɒriˈælɪs/, the traditional name of the system.[12] Based on parallax measurements, it is located at a distance of approximately 181 light years from the Sun. The star is drifting further away with a radial velocity of 29 km/s.[5] In 1910 this star was reported to be a spectroscopic binary by O. J. Lee,[13] but is now considered a single star.[14][15] Since it is near the ecliptic, it can be occulted by the Moon[16] and, very rarely, by planets.

Quick Facts Constellation, Right ascension ...

Nomenclature

γ Cancri (Latinised to Gamma Cancri) is the star's Bayer designation. It bore the traditional name Asellus Borealis (Latin for "northern donkey").[17] In 2016, the International Astronomical Union organized a Working Group on Star Names (WGSN)[18] to catalogue and standardize proper names for stars. The WGSN decided to attribute proper names to individual stars rather than entire multiple systems.[19] 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.[12] Together with Delta Cancri, it formed the Aselli, flanking Praesepe.[20]

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.[21] Gamma Cancri itself is known as the third star of Ghost (Chinese: 鬼宿三; pinyin: Guǐ Xiù sān).[22]

Properties

Gamma Cancri presents as a white A-type subgiant with an apparent magnitude of +4.67.[3] The star is an estimated 171[7] million years old and is spinning with a projected rotational velocity of 86 km/s.[10] It has 2.18[7] times the mass of the Sun and shines with a luminosity approximately 36 times greater at an effective temperature of 9108 K.[9]

It has been included as a member of the Hyades Stream based on its distance, space motion, and likely age.[23]

References

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    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.
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    Wilson, Ralph Elmer (1953). "General catalogue of stellar radial velocities". Carnegie Institute Washington D.C. Publication. Bibcode:1953GCRV..C......0W.
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    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.
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    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
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    Royer, F.; Grenier, S.; Baylac, M.-O.; Gómez, A. E.; Zorec, J. (2002). "Rotational velocities of A-type stars in the northern hemisphere. II. Measurement of v sin i". Astronomy and Astrophysics. 393: 897–911. arXiv:astro-ph/0205255. Bibcode:2002A&A...393..897R. doi:10.1051/0004-6361:20020943. S2CID 14070763.
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    Lee, Oliver J. (November 1910). "Measures on nineteen new spectroscopic binaries". Astrophysical Journal. 32: 300–308. Bibcode:1910ApJ....32..300L. doi:10.1086/141806.
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    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.
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    IAU Working Group on Star Names (WGSN), International Astronomical Union, retrieved 22 May 2016.
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    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.
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    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
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    Eggen, Olin J. (October 1992). "The Hyades Supercluster in FK5". Astronomical Journal. 104: 1482. Bibcode:1992AJ....104.1482E. doi:10.1086/116333.
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