Astronomy:Gamma Cancri
| Observation data Equinox J2000.0]] (ICRS) | |
|---|---|
| Constellation | Cancer[1] |
| Right ascension | 08h 43m 17.147s[2] |
| Declination | +21° 28′ 06.60″[2] |
| Apparent magnitude (V) | 4.673[1] |
| Characteristics | |
| Evolutionary stage | main sequence[3] |
| Spectral type | A1IV[4] |
| U−B color index | +0.03[5] |
| B−V color index | +0.010[1] |
| Astrometry | |
| Radial velocity (Rv) | 28.7[6] km/s |
| Proper motion (μ) | RA: −105.760[2] mas/yr Dec.: −39.157[2] mas/yr |
| Parallax (π) | 18.6431 ± 0.1900[2] mas |
| Distance | 175 ± 2 ly (53.6 ± 0.5 pc) |
| Absolute magnitude (MV) | +1.1[7] |
| Details | |
| Mass | 2.35±0.42[8] M☉ |
| Radius | 2.53±0.23[8] R☉ |
| Luminosity | 43.3±7.9[8] L☉ |
| Surface gravity (log g) | 4.00±0.25[8] cgs |
| Temperature | 9,311[8] K |
| Rotational velocity (v sin i) | 86±6[9] km/s |
| Age | 171[10] Myr |
| Other designations | |
| Database references | |
| SIMBAD | data |
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.[12] 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.[6]
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]
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.[4] The star is an estimated 171[10] million years old and is spinning with a projected rotational velocity of 86 km/s.[9] 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.[8]
It has been included as a member of the Hyades Stream based on its distance, space motion, and estimated age.[23]
References
- ↑ 1.0 1.1 1.2 Anderson, E.; Francis, Ch. (2012), "XHIP: An extended hipparcos compilation", Astronomy Letters 38 (5): 331, doi:10.1134/S1063773712050015, Bibcode: 2012AstL...38..331A.
- ↑ 2.0 2.1 2.2 2.3 Vallenari, A. et al. (2022). "Gaia Data Release 3. Summary of the content and survey properties". Astronomy & Astrophysics. doi:10.1051/0004-6361/202243940 Gaia DR3 record for this source at VizieR.
- ↑ Zorec, J.; Royer, F. (2012). "Rotational velocities of A-type stars. IV. Evolution of rotational velocities". Astronomy and Astrophysics 537: A120. doi:10.1051/0004-6361/201117691. Bibcode: 2012A&A...537A.120Z.
- ↑ 4.0 4.1 Abt, Helmut A.; Morrell, Nidia I. (1995). "The Relation between Rotational Velocities and Spectral Peculiarities among A-Type Stars". Astrophysical Journal Supplement 95: 135. doi:10.1086/192182. Bibcode: 1995ApJS...99..135A.
- ↑ Mermilliod, J.-C. (1986). "Compilation of Eggen's UBV data, transformed to UBV (unpublished)". Catalogue of Eggen's UBV Data. Bibcode: 1986EgUBV........0M.
- ↑ 6.0 6.1 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. doi:10.1086/114834. Bibcode: 1988AJ.....96..635E.
- ↑ 8.0 8.1 8.2 8.3 8.4 8.5 Stassun, Keivan G. (2019). "The Revised TESS Input Catalog and Candidate Target List". The Astronomical Journal 158 (4): 138. doi:10.3847/1538-3881/ab3467. Bibcode: 2019AJ....158..138S.
- ↑ 9.0 9.1 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. doi:10.1051/0004-6361:20020943. Bibcode: 2002A&A...393..897R.
- ↑ 10.0 10.1 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. doi:10.1088/0004-637X/804/2/146. Bibcode: 2015ApJ...804..146D. Vizier catalog entry
- ↑ "gam Cnc". SIMBAD. Centre de données astronomiques de Strasbourg. http://simbad.u-strasbg.fr/simbad/sim-basic?Ident=gam+Cnc.
- ↑ 12.0 12.1 "Naming Stars". IAU.org. https://www.iau.org/public/themes/naming_stars/.
- ↑ Lee, Oliver J. (November 1910). "Measures on nineteen new spectroscopic binaries". Astrophysical Journal 32: 300–308. doi:10.1086/141806. Bibcode: 1910ApJ....32..300L.
- ↑ 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. doi:10.1111/j.1365-2966.2008.13596.x. Bibcode: 2008MNRAS.389..869E.
- ↑ 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. doi:10.1111/j.1365-2966.2011.18765.x. Bibcode: 2011MNRAS.415..854D.
- ↑ Schmidtke, P. C.; Africano, J. L. (January 2011). "KPNO Lunar Occultation Summary. III". The Astronomical Journal 141 (1): 7. doi:10.1088/0004-6256/141/1/10. 10. Bibcode: 2011AJ....141...10S.
- ↑ Dixon-Kennedy, Mike (1998), Encyclopedia of Greco-Roman Mythology, ABC-CLIO, p. 51, ISBN 9781576070949, https://books.google.com/books?id=2U7okUE3PIcC&pg=PA51
- ↑ IAU Working Group on Star Names (WGSN), International Astronomical Union, https://www.iau.org/science/scientific_bodies/working_groups/280/, retrieved 22 May 2016.
- ↑ "WG Triennial Report (2015-2018) - Star Names". p. 5. https://www.iau.org/static/science/scientific_bodies/working_groups/280/wg-starnames-triennial-report-2015-2018.pdf.
- ↑ Allen, Richard H. (February 28, 2013). Star Names: Their Lore and Meaning. Courier Corporation. ISBN 978-0-486-13766-7. https://books.google.com/books?id=vWDsybJzz7IC.
- ↑ 陳久金 (2005). Zhōngguó Xīngzuò Shénhuà. 台灣古籍出版有限公司. p. 394. ISBN 978-986-7332-25-7. https://books.google.com/books?id=0Vex0rYzdu8C&pg=394.
- ↑ "Error: no
|title=specified when using {{Cite web}}" (in zh). http://www.lcsd.gov.hk/CE/Museum/Space/zh_TW/web/spm/starshine/resources/constemyth/chinengstars/startable1.html. "Asellus Borealis" - ↑ Eggen, Olin J. (October 1992). "The Hyades Supercluster in FK5". Astronomical Journal 104: 1482. doi:10.1086/116333. Bibcode: 1992AJ....104.1482E.
