Location of γ Cancri (circled) | |
Observation data Epoch J2000.0 Equinox J2000.0 (ICRS) | |
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Constellation | Cancer |
Right ascension | 08 43 17.14820 |
Declination | +21° 28′ 06.6008″ |
Apparent magnitude (V) | 4.673 |
Characteristics | |
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: −103.51 mas/yr Dec.: −39.48 mas/yr |
Parallax (π) | 18.00 ± 0.21 mas |
Distance | 181 ± 2 ly (55.6 ± 0.6 pc) |
Absolute magnitude (MV) | +1.1 |
Details | |
Mass | 2.18 M☉ |
Radius | 2.5 R☉ |
Luminosity | 36 L☉ |
Surface gravity (log g) | 4.17 cgs |
Temperature | 9,108 K |
Rotational velocity (v sin i) | 86±6 km/s |
Age | 171 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 | |
SIMBAD | data |
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. 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. 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 and, very rarely, by planets.
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 2.18 times the mass of the Sun and shines with a luminosity approximately 36 times greater at an effective temperature of 9108 K.
It has been included as a member of the Hyades Stream based on its distance, space motion, and likely age.
References
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- ^ 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.
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- Mermilliod, J.-C. (1986). "Compilation of Eggen's UBV data, transformed to UBV (unpublished)". Catalogue of Eggen's UBV Data. Bibcode:1986EgUBV........0M.
- ^ Wilson, Ralph Elmer (1953). "General catalogue of stellar radial velocities". Carnegie Institute Washington D.C. Publication. Bibcode:1953GCRV..C......0W.
- 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.
- ^ 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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- ^ McDonald, I.; Zijlstra, A. A.; Boyer, M. L. (2012). "Fundamental Parameters and Infrared Excesses of Hipparcos Stars". Monthly Notices of the Royal Astronomical Society. 427 (1): 343–57. arXiv:1208.2037. Bibcode:2012MNRAS.427..343M. doi:10.1111/j.1365-2966.2012.21873.x. S2CID 118665352.
- ^ 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 (3): 897–911. arXiv:astro-ph/0205255. Bibcode:2002A&A...393..897R. doi:10.1051/0004-6361:20020943. S2CID 14070763.
- "gam Cnc". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 8 April 2015.
- ^ "Naming Stars". IAU.org. Retrieved 16 December 2017.
- Lee, Oliver J. (November 1910). "Measures on nineteen new spectroscopic binaries". Astrophysical Journal. 32: 300–308. Bibcode:1910ApJ....32..300L. doi:10.1086/141806.
- 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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- 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.
- Dixon-Kennedy, Mike (1998), Encyclopedia of Greco-Roman Mythology, ABC-CLIO, p. 51, ISBN 9781576070949
- IAU Working Group on Star Names (WGSN), International Astronomical Union, retrieved 22 May 2016.
- "WG Triennial Report (2015-2018) - Star Names" (PDF). p. 5. Retrieved 2018-07-14.
- Richard H. Allen (28 February 2013). Star Names: Their Lore and Meaning. Courier Corporation. ISBN 978-0-486-13766-7.
- 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.
- 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
- 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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