Alpha Cancri

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Acubens, α Cancri
Cancer constellation map.png
Acubens is the α star in the "crab"
Observation data
Epoch J2000.0      Equinox J2000.0 (ICRS)
Constellation Cancer
Right ascension 08h 58m 29.2217s[1]
Declination +11° 51′ 27.723″[1]
Apparent magnitude (V) 4.20 to 4.27[2]
Characteristics
Spectral type A5m[1]
U−B color index +0.15[3]
B−V color index +0.14[3]
R−I color index +0.04[3]
Astrometry
Radial velocity (Rv) −13.8 ± 2[1] km/s
Proper motion (μ) RA: 41.45[1] mas/yr
Dec.: −29.22[1] mas/yr
Parallax (π) 18.79 ± 0.99[4] mas
Distance 174 ± 9 ly
(53 ± 3 pc)
Absolute magnitude (MV) 0.6[5]
Details
Mass 2[6] M
Radius 1.0[7] R
Luminosity 23[6] L
Rotational velocity (v sin i) 75[8] km/s
Other designations
Acubens, Sertan, Sartan, α Cnc, Alpha Cancri, Alpha Cnc, 65 Cancri, 65 Cnc, ADS 7115 A, BD+12 1948, CCDM J08585+1151A, FK5 337, GC 12406, HD 76756, HIP 44066, HR 3572, IDS 08530+1215 A, PPM 125972, SAO 98267.[1][3]
Database references
SIMBAD data

Alpha Cancri (α Cnc, α Cancri) is a star system in the constellation Cancer. It has the traditional name Acubens (Açubens), from the Arabic الزوبنةal zubanāh, "the claws" [9]

Properties[edit]

Acubens is a fourth-magnitude star with an apparent magnitude of 4.20, making it barely visible to the naked eye under good lighting conditions. Nevertheless, it is 23 times more luminous than the Sun. Its stellar classification is A5m. The Hipparcos mission estimated the distance of Acubens to be roughly 53 parsecs[4] from Earth, or approximately 174 light years away.

Since it is near the ecliptic, it can be occulted by the Moon and very rarely by planets.

Star System[edit]

The primary component, α Cancri A, is a white A-type main sequence dwarf with an apparent magnitude of +4.26. 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.[10][11]

From studying its light curve during occultation, it is thought that α Cancri A may itself be a close binary, consisting of two stars with similar brightness and a separation of 0.1 arcseconds.[3]

Acubens in Military[edit]

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

See also[edit]

References[edit]

  1. ^ a b c d e f g "SIMBAD query result: alf Cnc -- Variable Star". Centre de Données astronomiques de Strasbourg. Retrieved 2009-09-20. 
  2. ^ NSV 4327, database entry, New Catalogue of Suspected Variable Stars, the improved version, Sternberg Astronomical Institute, Moscow, Russia. Accessed on line October 20, 2009.
  3. ^ a b c d e HR 3572, database entry, The Bright Star Catalogue, 5th Revised Ed. (Preliminary Version), D. Hoffleit and W. H. Warren, Jr., CDS ID V/50. Accessed on line October 20, 2009.
  4. ^ a b Perryman, M. A. C. et al. (1997), The Hipparcos Catalogue, Astronomy & Astrophysics 323: L49–L52, Bibcode:1997A&A...323L..49P 
  5. ^ From apparent magnitude and parallax.
  6. ^ a b Professor James B. (Jim) Kaler. "ACUBENS (Alpha Cancri)". University of Illinois. Retrieved 2010-05-13. 
  7. ^ HD 76756, database entry, Catalog of Apparent Diameters and Absolute Radii of Stars (CADARS), 3rd edition, L. E. Pasinetti-Fracassini, L. Pastori, S. Covino, and A. Pozzi, CDS ID II/224. Accessed on line October 20, 2009.
  8. ^ 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 in the northern hemisphere". Astronomy and Astrophysics (PDF) 393 (3): 897–911. arXiv:astro-ph/0205255. Bibcode:2002A&A...393..897R. doi:10.1051/0004-6361:20020943. 
  9. ^ Richard Hinckley Allen: Star Names — Their Lore and Meaning: Cancer
  10. ^ "CCDM (Catalog of Components of Double & Multiple stars (Dommanget+ 2002)". VizieR. Centre de Données astronomiques de Strasbourg. Retrieved 2010-05-13. 
  11. ^ "Acubens". Alcyone Bright Star Catalogue. Retrieved 2010-05-13. 

External links[edit]

  • Jim Kaler's Stars, University of Illinois:Acubens