25 Cancri
Star in the constellation Cancer
25 Cancri is a common proper motion [ 4] star system in the zodiac constellation of Cancer , located around 148 light-years away from the Sun . It has the Bayer designation d2 Cancri (d2 Cnc); 25 Cancri (25 Cnc) is the Flamsteed designation . It is near the lower limit of visibility to the naked eye in good viewing conditions, appearing as a dim, yellow-white-hued star with a combined apparent visual magnitude of 6.11.[ 2] The pair have a relatively high proper motion , traversing the celestial sphere at an angular rate of 0.245″ per year.[ 9] It is moving further from the Earth with a heliocentric radial velocity of +38 km/s.[ 1]
Based upon a stellar classification of F6 V,[ 3] the brighter component is an F-type main-sequence star that is generating energy through hydrogen fusion at its core. Cowley (1976) listed a class of F5 IIIm?,[ 10] which suggests it may be an Am star . However, this has not been confirmed.[ 6] It is about 2.5[ 5] billion years old with 1.51[ 4] times the mass of the Sun . The star is radiating 6.6[ 2] times the Sun's luminosity from its photosphere at an effective temperature of 6,487 K .[ 5]
The companion is 4.19 magnitudes fainter than the primary, and lies at an angular separation of 16.798″ along a position angle of 310°, as of 2013.[ 8] If the pair are gravitationally bound , then they orbit each other with a period of around 4.05 million years.[ 4]
References
^ a b c d e f g h Vallenari, A.; et al. (Gaia collaboration) (2023). "Gaia Data Release 3. Summary of the content and survey properties" . Astronomy and Astrophysics . 674 : A1. arXiv :2208.00211 . Bibcode :2023A&A...674A...1G . doi :10.1051/0004-6361/202243940 . S2CID 244398875 .
Gaia DR3 record for this source at VizieR .
^ a b c d e f 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 Harlan, E. A. (September 1969), "MK classifications for F- and G-type stars. I", Astronomical Journal , 74 : 916–919, Bibcode :1969AJ.....74..916H , doi :10.1086/110881 .
^ a b c d e Tokovinin, Andrei (2014), "From Binaries to Multiples. II. Hierarchical Multiplicity of F and G Dwarfs", The Astronomical Journal , 147 (4): 87, arXiv :1401.6827 , Bibcode :2014AJ....147...87T , doi :10.1088/0004-6256/147/4/87 , S2CID 56066740 .
^ a b c d e f Casagrande, L.; et al. (June 2011), "New constraints on the chemical evolution of the solar neighbourhood and Galactic disc(s). Improved astrophysical parameters for the Geneva-Copenhagen Survey", Astronomy and Astrophysics , 530 : A138, arXiv :1103.4651 , Bibcode :2011A&A...530A.138C , doi :10.1051/0004-6361/201016276 , S2CID 56118016 .
^ a b LeBlanc, F.; et al. (November 2015), "Project VeSElkA: results of abundance analysis I - HD 71030, HD 95608, HD 116235 and HD 186568", Monthly Notices of the Royal Astronomical Society , 453 (4): 3766–3771, Bibcode :2015MNRAS.453.3766L , doi :10.1093/mnras/stv1466 .
^ "25 Cnc" . SIMBAD . Centre de données astronomiques de Strasbourg . Retrieved 2019-02-25 .
^ a b Riddle, Reed L.; et al. (January 1, 2015), "A Survey of the High Order Multiplicity of Nearby Solar-type Binary Stars with Robo-AO", The Astrophysical Journal , 799 (1): 4, arXiv :1411.0682 , Bibcode :2015ApJ...799....4R , doi :10.1088/0004-637X/799/1/4 , ISSN 0004-637X , S2CID 5642378 .
^ Lépine, Sébastien; Shara, Michael M. (March 2005), "A Catalog of Northern Stars with Annual Proper Motions Larger than 0.15" (LSPM-NORTH Catalog)", The Astronomical Journal , 129 (3): 1483–1522, arXiv :astro-ph/0412070 , Bibcode :2005AJ....129.1483L , doi :10.1086/427854 , S2CID 2603568 .
^ Cowley, A. P. (April 1976), "Spectral classification of the bright F stars", Publications of the Astronomical Society of the Pacific , 88 : 95–110, Bibcode :1976PASP...88...95C , doi :10.1086/129905 .