38 Cancri
| Observation data EpochJ2000.0EquinoxJ2000.0 | |
|---|---|
| Constellation | Cancer |
| Right ascension | 08h39m42.65445s[2] |
| Declination | +19° 46′ 42.4386″[2] |
| Apparent magnitude(V) | 6.65[3] |
| Characteristics | |
| Evolutionary stage | subgiant |
| Spectral type | F0 IV[4] |
| B−Vcolor index | 0.248±0.010[3] |
| Variable type | δ Sct[5] |
| Astrometry | |
| Radial velocity(Rv) | +32.0±2.0[6]km/s |
| Proper motion(μ) | RA:−36.879[2]mas/yr Dec.:−13.103[2]mas/yr |
| Parallax(π) | 5.3700 ± 0.0705mas[2] |
| Distance | 607 ± 8ly (186 ± 2pc) |
| Absolute magnitude(MV) | 0.36[3] |
| Details | |
| Mass | 1.786[7]M☉ |
| Radius | 1.834[7]R☉ |
| Luminosity | 59.31[3]L☉ |
| Surface gravity(logg) | 2.92±0.20[8]cgs |
| Temperature | 7300±200[8]K |
| Metallicity[Fe/H] | −0.16±0.10[8]dex |
| Rotation | 0.670 d[7] |
| Rotational velocity(vsini) | 138.5[7]km/s |
| Other designations | |
| Database references | |
| SIMBAD | data |
38 Cancriis avariable starin thezodiacconstellationCancer,located around 607light yearsfrom the Sun. This object has thevariable star designationBT Cancri;38 Cancriis theFlamsteed designation.It is a member of thePraesepe cluster[10]but is a challenge to view with the naked eye, having anapparent visual magnitudeof 6.65.[3]The star is moving closer to the Earth with a heliocentricradial velocityof +32 km/s.[6]
This is anevolvingsubgiant starwith astellar classificationof F0 IV.[4]It was found to be a pulsating variable by Michel Breger in 1970[11]and is classed as aDelta Scuti variable.The star displays a pattern of variation showing up to 22 differentfrequencies,with three being dominant.[12]The brightness varies by up to 0.07 in magnitude.[5]The star has amagnetic fieldwith a computed longitudinal field strength of−215±149G.[8]It has 1.8[7]times themass of the Sunand 1.8[7]times theSun's radius.The star is radiating 59[3]times theSun's luminosityfrom itsphotosphereat aneffective temperatureof around 7,300 K.[8]
References
[edit]- ^Gupta, S. K. (September 1979)."Light Variation of the Delta Scuti Star 38 CNC".Bulletin of the Astronomical Society of India.7:72–77.Bibcode:1979BASI....7...72G.Retrieved11 November2021.
- ^abcdeBrown, A. G. A.;et al. (Gaia collaboration) (August 2018)."GaiaData Release 2: Summary of the contents and survey properties ".Astronomy & Astrophysics.616.A1.arXiv:1804.09365.Bibcode:2018A&A...616A...1G.doi:10.1051/0004-6361/201833051.Gaia DR2 record for this sourceatVizieR.
- ^abcdefAnderson, 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,S2CID119257644.
- ^abGray, R. O.; et al. (April 2001), "The Physical Basis of Luminosity Classification in the Late A-, F-, and Early G-Type Stars. I. Precise Spectral Types for 372 Stars",The Astronomical Journal,121(4): 2148–2158,Bibcode:2001AJ....121.2148G,doi:10.1086/319956.
- ^abSamus, N. N.; et al. (2017), "General Catalogue of Variable Stars",Astronomy Reports,5.1,61(1): 80–88,Bibcode:2017ARep...61...80S,doi:10.1134/S1063772917010085,S2CID125853869.
- ^abde 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,S2CID59451347,A61.
- ^abcdefvan Saders, Jennifer L.; Pinsonneault, Marc H. (October 2013), "Fast Star, Slow Star; Old Star, Young Star: Subgiant Rotation as a Population and Stellar Physics Diagnostic",The Astrophysical Journal,776(2): 20,arXiv:1306.3701,Bibcode:2013ApJ...776...67V,doi:10.1088/0004-637X/776/2/67,S2CID119097746,67.
- ^abcdeFossati, L.; et al. (December 2007), "Late stages of the evolution of A-type stars on the main sequence: comparison between observed chemical abundances and diffusion models for 8 Am stars of the Praesepe cluster",Astronomy and Astrophysics,476(2): 911–925,arXiv:0710.0579,Bibcode:2007A&A...476..911F,doi:10.1051/0004-6361:20078320,S2CID16152096.
- ^"38 Cnc".SIMBAD.Centre de données astronomiques de Strasbourg.Retrieved2019-03-01.
- ^Michel, E.; et al. (February 1999), "Seismology of delta Scuti stars in the Praesepe cluster. I. Ranges of unstable modes as predicted by linear analysis versus observations",Astronomy and Astrophysics,342:153–166,Bibcode:1999A&A...342..153M.
- ^Breger, Michel (November 1970), "Metallic-Line a Stars and Pulsation",Astrophysical Journal,162:597,Bibcode:1970ApJ...162..597B,doi:10.1086/150691
- ^Breger, M.; et al. (February 2012), "Delta Scuti stars in the Praesepe cluster observed by the MOST satellite",Astronomische Nachrichten,333(2): 131,arXiv:1201.0892,Bibcode:2012AN....333..131B,doi:10.1002/asna.201111640,S2CID118458884.
