Star system in the constellation Cancer
α Cancri α Cancri, circled, is the bottom left star in the "crab".
Observation dataEpoch J2000.0 Equinox J2000.0 (ICRS ) Constellation Cancer Right ascension 08h 58m 29.2042s [ 1] Declination +11° 51′ 27.649″[ 1] Apparent magnitude (V)4.20 to 4.27[ 2] Characteristics Spectral type kA7VmF0/2III/IVSr[ 3] U−Bcolor index +0.15[ 4] B−Vcolor index +0.14[ 4] R−Icolor index +0.04[ 4] Astrometry Radial velocity (Rv )± 0.8[ 5] km/s Proper motion (μ)RA: 42.181[ 1] mas /yr Dec.: −31.160[ 1] mas /yr Parallax (π)18.3304± 0.3216 mas [ 1] Distance 178 ± 3 ly pc ) Absolute magnitude (MV )0.46[ 6] Details A Mass 2.10[ 7] M ☉ Radius 3.655[ 8] R ☉ Luminosity 49[ 8] L ☉ Temperature 7,943[ 9] K Metallicity 3.73[ 9] Rotational velocity (v sin i )75[ 10] B Mass 0.38[ 7] M ☉ Other designations Acubens, Sertan, Sartan,[ 4] 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[ 11] Database references SIMBAD data B
Alpha Cancri (α Cancri , abbreviatedAlpha Cnc ,α Cnc , namedAcubens /ˈ æ k juː b ɛ n z [ 12] star system in theconstellation ofCancer .
α Cancri (Latinised toAlpha Cancri ) is the star'sBayer designation .
The traditional nameAcubens (Açubens) is derived from the Arabicالزبانى al zubanāh [ 13] /ˈ s ɜːr t æ n al-saraṭān , 'the crab'. TheInternational Astronomical Union Working Group on Star Names (WGSN) choose 'Acubens' as the proper name for the primary component of this star.[ 14]
α Cancri is a fourth-magnitudestar with anapparent magnitude of 4.20, making it barely visible to the naked eye under good lighting conditions. Nevertheless, it is 23 times moreluminous than the Sun. Itsstellar classification is given as kA7VmF0/2III/IVSr, indicating anAm star withcalcium K-lines similar to an A7main sequence star and hydrogen lines more like an F0giant orsubgiant star. The distance of α Cancri calculated from theGaia Data Release 2 parallax is roughly 50parsecs fromEarth , or approximately 164light-years away.
Since it is near theecliptic , it can beocculted by theMoon and very rarely byplanets .
The primary component, α Cancri A, is a whiteA-type main-sequence dwarf with anapparent magnitude of +4.26. Its companion, α Cancri B, is an eleventh-magnitude star. In the year 1836, itsposition angle was observed at 325 degrees with a separation from the main star α Cancri A of 11.3arcseconds .[ 15] [ 16]
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.[ 4]
USSAcubens (AKS-5) was aUnited States Navy ship.
^a b c d e 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 atVizieR .^ NSV 4327, database entry,New Catalogue of Suspected Variable Stars, the improved version , Sternberg Astronomical Institute, Moscow, Russia. Accessed on line October 20, 2009. ^ 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 . ^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 IDV/50 . Accessed on line October 20, 2009.^ 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 . ^ 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 . ^a b 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 ^a b McDonald, I.; Zijlstra, A. A.; Watson, R. A. (2017-10-01)."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 atVizieR .^a b Baines, Ellyn K.; Armstrong, J. Thomas; Schmitt, Henrique R.; Zavala, R. T.; Benson, James A.; Hutter, Donald J.; Tycner, Christopher; Van Belle, Gerard T. (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 . ^ 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 .S2CID 14070763 . ^ "alf Cnc" .SIMBAD Centre de données astronomiques de Strasbourg . Retrieved2009-09-20 .^ 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 Pub.ISBN 978-1-931559-44-7 ^ Richard Hinckley Allen: Star Names — Their Lore and Meaning: Cancer ^ "Naming Stars" .International Astronomical Union . Retrieved2018-11-04 .^ "CCDM (Catalog of Components of Double & Multiple stars (Dommanget+ 2002)" .VizieR Centre de Données astronomiques de Strasbourg . Retrieved2010-05-13 .^ "Acubens" . Alcyone Bright Star Catalogue. Retrieved2010-05-13 .Jim Kaler's Stars, University of Illinois:Acubens
