28 Cancri
Binary star in the constellation Cancer
28 Cancri is a star system in the zodiac constellation of Cancer . It is a variable star with the designation CX Cancri , and is close to the lower limit of visibility with the naked eye, having a mean apparent visual magnitude of 6.05.[ 3] The annual parallax shift seen from Earth's orbit is 8.5 mas , which provides a distance estimate of about 384 light years . It is moving away from the Sun with a radial velocity of around +9 km/s.[ 6]
Based upon proper motion variation, this is an astrometric binary system with high likelihood (99.8%).[ 11] The visible component has a stellar classification of F0 Vn,[ 4] indicating it is a F-type main-sequence star with "nebulous" lines due to rapid rotation. It is a Delta Scuti variable star with a period of 0.0960 days and an amplitude of 0.020 in magnitude.[ 12] With 2.4 times the mass of the Sun it is spinning with a high projected rotational velocity of 133 km/s. 28 Cancri is radiating roughly 44 times the Sun's luminosity from its photosphere at an effective temperature of around 7,516 K.
References
^ "MAST: Barbara A. Mikulski Archive for Space Telescopes" . Space Telescope Science Institute. Retrieved 8 December 2021 .
^ a b c d e f g h i 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 Oja, T. (August 1991), "UBV photometry of stars whose positions are accurately known. VI", Astronomy and Astrophysics Supplement Series , 89 (2): 415–419, Bibcode :1991A&AS...89..415O .
^ a b Cowley, A.; et al. (April 1969), "A study of the bright A stars. I. A catalogue of spectral classifications", Astronomical Journal , 74 : 375–406, Bibcode :1969AJ.....74..375C , doi :10.1086/110819 .
^ Dubath, P.; et al. (2011), "Random forest automated supervised classification of Hipparcos periodic variable stars", Monthly Notices of the Royal Astronomical Society , 414 (3): 2602–2617, arXiv :1101.2406 , Bibcode :2011MNRAS.414.2602D , doi :10.1111/j.1365-2966.2011.18575.x , S2CID 118560311 .
^ a b de Bruijne, J. H. J.; Eilers, A.-C. (October 2012), "Radial velocities for the HIPPARCOS-Gaia Hundred-Thousand-Proper-Motion project", Astronomy & Astrophysics , 546 : 14, arXiv :1208.3048 , Bibcode :2012A&A...546A..61D , doi :10.1051/0004-6361/201219219 , S2CID 59451347 , A61.
^ 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 c Zorec, J.; Royer, F. (2012), "Rotational velocities of A-type stars. IV. Evolution of rotational velocities", Astronomy & Astrophysics , 537 : A120, arXiv :1201.2052 , Bibcode :2012A&A...537A.120Z , doi :10.1051/0004-6361/201117691 , S2CID 55586789 , A120.
^ Netopil, Martin (4 May 2017). "Metallicity calibrations for dwarf stars and giants in the Geneva photometric system" . Monthly Notices of the Royal Astronomical Society . 469 (3): 3042–3055. arXiv :1705.00883 . Bibcode :2017MNRAS.469.3042N . doi :10.1093/mnras/stx1077 . eISSN 1365-2966 . ISSN 0035-8711 .
^ "28 Cnc" . SIMBAD . Centre de données astronomiques de Strasbourg . Retrieved 2018-02-09 .
^ Frankowski, A.; et al. (March 2007), "Proper-motion binaries in the Hipparcos catalogue. Comparison with radial velocity data", Astronomy and Astrophysics , 464 (1): 377–392, arXiv :astro-ph/0612449 , Bibcode :2007A&A...464..377F , doi :10.1051/0004-6361:20065526 , S2CID 14010423 .
^ Rodríguez, E.; et al. (June 2000), "A revised catalogue of δ Sct stars", Astronomy and Astrophysics Supplement , 144 (3): 469–474, Bibcode :2000A&AS..144..469R , doi :10.1051/aas:2000221 , hdl :10261/226673 .