Jump to content

Alpha Cancri

Coordinates: Sky map 08h 58m 29.2217s, +11° 51′ 27.723″
From Wikipedia, the free encyclopedia
(Redirected from Acubens)
α Cancri
α Cancri, circled, is the bottom left star in the "crab".
Observation data
Epoch J2000.0      Equinox J2000.0 (ICRS)
Constellation Cancer[1]
Right ascension 08h 58m 29.2042s[2]
Declination +11° 51′ 27.649″[2]
Apparent magnitude (V) 4.20 to 4.27[3]
Characteristics
Spectral type kA7VmF0/2III/IVSr[4]
U−B color index +0.15[5]
B−V color index +0.14[5]
R−I color index +0.04[5]
Astrometry
Radial velocity (Rv)−12.1±0.8[6] km/s
Proper motion (μ) RA: 42.181 mas/yr[2]
Dec.: −31.160 mas/yr[2]
Parallax (π)18.3304±0.3216 mas[2]
Distance178 ± 3 ly
(54.6 ± 1.0 pc)
Absolute magnitude (MV)0.46[1]
Details
A
Mass2.10[7] M☉
Radius3.655[8] R☉
Luminosity49[8] L☉
Surface gravity (log g)3.73[9] cgs
Temperature7,943[9] K
Rotational velocity (v sin i)75[10] km/s
B
Mass0.38[7] M☉
Other designations
Acubens, Sertan, Sartan[5], α Cnc, Alpha Cancri, Alpha Cnc, 65 Cancri, 65 Cnc, BD+12 1948, FK5 337, GC 12406, HD 76756, HIP 44066, HR 3572, SAO 98267, PPM 125972, ADS 7115 A, CCDM J08585+1151A[11]
Database references
SIMBADdata
B

Alpha Cancri is a star system in the northern constellation of Cancer. Its name is a Bayer designation that is Latinized from α Cancri, and abbreviated Alpha Cnc or α Cnc. The primary component has the proper name Acubens, pronounced /ˈækjuːbɛnz/.[12] It forms a fourth-magnitude star with an apparent magnitude of 4.20, making it barely visible to the naked eye under good viewing conditions. Based on parallax measurements, it is located at a distance of 178 light-years (55 pc) from the Sun, but is drifting closer with a radial velocity of −12 km/s.[6] Since it is near the ecliptic, it can be occulted by the Moon.[13]

Properties

[edit]

The primary component, α Cancri A, has a stellar classification of kA7VmF0/2III/IVSr, indicating an Am star with calcium K-lines similar to an A7 main sequence star and hydrogen lines more like an F0 giant or subgiant star. It is a white A-type main-sequence star with an apparent magnitude of +4.26. The star has 2.10[7] times the mass of the Sun and 3.7[8] times the Sun's radius. It has a high rate of spin, showing a projected rotational velocity of 75 km/s.[10] The star is radiating 49 times the luminosity of the Sun from its photosphere at an effective temperature of 7,943 K.[9]

Its companion, α Cancri B, is an eleventh-magnitude star. In the year 1836, its position angle was observed at 325 degrees with a separation from the main star α Cancri A of 11.3 arcseconds.[14][15] α Cancri A may itself be a close binary, consisting of two stars with similar brightness and a separation of 0.1 arcsecond, though this is questioned.[5] Indeed, a light curve generated during a 2014 lunar occultation failed to demonstrate a close companion.[13]

Nomenclature

[edit]

α Cancri (Latinised to Alpha Cancri) is the star's Bayer designation.

The traditional name Acubens (Açubens) is derived from the Arabic الزبانى al zubanāh, 'the claws'.[16] A second name, Sertan /ˈsɜːrtæn/, derives from the Arabic al-saraṭān, 'the crab'. The International Astronomical Union Working Group on Star Names (WGSN) choose 'Acubens' as the proper name for the primary component of this star.[17]

In modern culture

[edit]

USS Acubens (AKS-5) was a United States Navy ship.

References

[edit]
  1. ^ a b 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. XHIP record for this object at VizieR.
  2. ^ a b c d Brown, A. G. A.; et al. (Gaia collaboration) (2021). "Gaia Early Data Release 3: Summary of the contents and survey properties". Astronomy & Astrophysics. 649: A1. arXiv:2012.01533. Bibcode:2021A&A...649A...1G. doi:10.1051/0004-6361/202039657. S2CID 227254300. (Erratum: doi:10.1051/0004-6361/202039657e). Gaia EDR3 record for this source at VizieR.
  3. ^ "NSV 4327, database entry". New Catalogue of Suspected Variable Stars, the improved version. Moscow, Russia: Sternberg Astronomical Institute. Retrieved October 20, 2009.
  4. ^ Sreedhar Rao, S.; Abhyankar, K. D. (1991). "MK morphological study of AM stars at 66 A/Mm". Journal of Astrophysics and Astronomy. 12 (2): 133. Bibcode:1991JApA...12..133S. doi:10.1007/BF02709302. S2CID 59324843.
  5. ^ a b c d e Hoffleit, D.; Warren, Jr., W. H. "HR 3572, database entry". The Bright Star Catalogue (5th Revised (Preliminary Version) ed.). Centre de Données astronomiques de Strasbourg. V/50. Retrieved October 20, 2009.
  6. ^ a b Gontcharov, G. A. (2006). "Pulkovo Compilation of Radial Velocities for 35 495 Hipparcos stars in a common system". Astronomy Letters. 32 (11): 759–771. arXiv:1606.08053. Bibcode:2006AstL...32..759G. doi:10.1134/S1063773706110065. S2CID 119231169.
  7. ^ a b c Tokovinin, A. A. (1997). "MSC - a catalogue of physical multiple stars". Astronomy and Astrophysics Supplement Series. 124: 75–84. Bibcode:1997A&AS..124...75T. doi:10.1051/aas:1997181.
  8. ^ a b c McDonald, I.; et al. (October 2017). "Fundamental parameters and infrared excesses of Tycho-Gaia stars". Monthly Notices of the Royal Astronomical Society. 471: 770–791. arXiv:1706.02208. Bibcode:2017MNRAS.471..770M. doi:10.1093/mnras/stx1433. ISSN 0035-8711. Acubens' database entry at VizieR.
  9. ^ a b c Baines, Ellyn K.; et al. (2018). "Fundamental Parameters of 87 Stars from the Navy Precision Optical Interferometer". The Astronomical Journal. 155 (1): 30. arXiv:1712.08109. Bibcode:2018AJ....155...30B. doi:10.3847/1538-3881/aa9d8b. S2CID 119427037.
  10. ^ a b Royer, F.; et al. (2002). "Rotational velocities of A-type stars in the northern hemisphere. II. Measurement of v sin i in the northern hemisphere". Astronomy and Astrophysics. 393 (3): 897–911. arXiv:astro-ph/0205255. Bibcode:2002A&A...393..897R. doi:10.1051/0004-6361:20020943. S2CID 14070763.
  11. ^ "alf Cnc". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2009-09-20.
  12. ^ Kunitzsch, Paul; Smart, Tim (2006). A Dictionary of Modern star Names: A Short Guide to 254 Star Names and Their Derivations (2nd rev. ed.). Cambridge, Massachusetts: Sky Publishing. ISBN 978-1-931559-44-7.
  13. ^ a b Richichi, A.; et al. (November 2014). "First Lunar Occultation Results from the 2.4 m Thai National Telescope Equipped with ULTRASPEC". The Astronomical Journal. 148 (5). arXiv:1408.0073. Bibcode:2014AJ....148..100R. doi:10.1088/0004-6256/148/5/100. 100.
  14. ^ "CCDM (Catalog of Components of Double & Multiple stars (Dommanget+ 2002)". VizieR. Centre de Données astronomiques de Strasbourg. Retrieved 2010-05-13.
  15. ^ "Acubens". Alcyone Bright Star Catalogue. Retrieved 2010-05-13.
  16. ^ Allen, Richard Hinckley (1963). "Star Names — Their Lore and Meaning: Cancer" (Dover ed.). Retrieved 2025-05-18.
  17. ^ "Naming Stars". International Astronomical Union. Retrieved 2018-11-04.
[edit]
  • Kaler, Jim. "Acubens". Stars. University of Illinois. Retrieved 2025-06-18.


Retrieved from "https://en.wikipedia.org/w/index.php?title=Alpha_Cancri&oldid=1296225486"