64 Eridani

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64 Eridani
Observation data
Epoch J2000      Equinox
Constellation Eridanus
Right ascension 04h 59m 55.73677s[1]
Declination −12° 32′ 14.6983″[1]
Apparent magnitude (V) 4.77[2]
Characteristics
Spectral type F0 V[3]
B−V color index 0.266[2]
Variable type δ Sct[4]
Astrometry
Radial velocity (Rv)−8.9±4.2[5] km/s
Proper motion (μ) RA: +39.67[1] mas/yr
Dec.: −87.04[1] mas/yr
Parallax (π)12.0106 ± 0.2199 mas[6]
Distance272 ± 5 ly
(83 ± 2 pc)
Absolute magnitude (MV)0.03[7]
Details
Mass1.52[8] M
Luminosity80.17[7] L
Surface gravity (log g)3.37[8] cgs
Temperature7,346±250[8] K
Rotational velocity (v sin i)212[9] km/s
Age644[8] Myr
Other designations
64 Eri, S Eri, BD−12° 1047, HD 32045, HIP 23231, HR 1611, SAO 150064[10]
Database references
SIMBADdata

64 Eridani is a single,[11] yellow-white hued star in the constellation Eridanus having variable star designation S Eridani. It is faintly visible to the naked eye with an apparent visual magnitude of 4.77.[2] The annual parallax shift is measured at 12.01 mas, which equates to a distance of about 272 light years.[6] In addition to its proper motion, it is moving closer to the Sun with a radial velocity of around −9 km/s.[5]

This is an F-type main-sequence star with a stellar classification of F0 V.[3] It is catalogued a low amplitude Delta Scuti variable with a primary period of 0.273 days.[4] It was originally classified, tentatively, as an RR Lyrae variable of type 'c'.[12]

64 Eridani is spinning rapidly with a projected rotational velocity of 212 km/s.[9] This is giving the star an oblate shape with an equatorial bulge; its equatorial radius is 8% larger than its polar radius.[13] The star is an estimated 644 million years old with 1.5 times the mass of the Sun.[8] It is radiating 80[7] times the Sun's luminosity from its photosphere at an effective temperature of roughly 7,346 K.[8]

References

  1. ^ a b c d van Leeuwen, F. (November 2007), "Validation of the new Hipparcos reduction", Astronomy and Astrophysics, 474 (2): 653–664, arXiv:0708.1752, Bibcode:2007A&A...474..653V, doi:10.1051/0004-6361:20078357.
  2. ^ a b c Høg, E.; et al. (2000), "The Tycho-2 catalogue of the 2.5 million brightest stars", Astronomy and Astrophysics, 355: L27, Bibcode:2000A&A...355L..27H, doi:10.1888/0333750888/2862.
  3. ^ a b Houk, Nancy; Smith-Moore, M. (1978), Michigan catalogue of two-dimensional spectral types for the HD stars, vol. 4, Ann Arbor: Dept. of Astronomy, University of Michigan, Bibcode:1988mcts.book.....H.
  4. ^ a b Rodríguez, E.; Breger, M. (January 2001), "delta Scuti and related stars: Analysis of the R00 Catalogue", Astronomy and Astrophysics, 366: 178–196, Bibcode:2001A&A...366..178R, doi:10.1051/0004-6361:20000205.
  5. ^ 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, A61.
  6. ^ a b Brown, A. G. A.; et al. (Gaia collaboration) (August 2018). "Gaia Data 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 source at VizieR.
  7. ^ a b c 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.
  8. ^ a b c d e f David, Trevor J.; Hillenbrand, Lynne A. (2015), "The Ages of Early-Type Stars: Strömgren Photometric Methods Calibrated, Validated, Tested, and Applied to Hosts and Prospective Hosts of Directly Imaged Exoplanets", The Astrophysical Journal, 804 (2): 146, arXiv:1501.03154, Bibcode:2015ApJ...804..146D, doi:10.1088/0004-637X/804/2/146.
  9. ^ a b Royer, F.; et al. (February 2007), "Rotational velocities of A-type stars. III. Velocity distributions", Astronomy and Astrophysics, 463 (2): 671–682, arXiv:astro-ph/0610785, Bibcode:2007A&A...463..671R, doi:10.1051/0004-6361:20065224.
  10. ^ "64 Eri". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2018-01-29.
  11. ^ Eggleton, P. P.; Tokovinin, A. A. (September 2008), "A catalogue of multiplicity among bright stellar systems", Monthly Notices of the Royal Astronomical Society, 389 (2): 869–879, arXiv:0806.2878, Bibcode:2008MNRAS.389..869E, doi:10.1111/j.1365-2966.2008.13596.x.
  12. ^ Samus, N. N.; Durlevich, O. V.; et al. (2009), "VizieR Online Data Catalog: General Catalogue of Variable Stars (Samus+ 2007-2013)", VizieR On-line Data Catalog: B/GCVS. Originally Published in: 2009yCat....102025S, 1: B/gcvs, Bibcode:2009yCat....102025S
  13. ^ Belle, G. T. (2012). "Interferometric observations of rapidly rotating stars". The Astronomy and Astrophysics Review. 20: 51. arXiv:1204.2572. Bibcode:2012A&ARv..20...51V. doi:10.1007/s00159-012-0051-2.{{cite journal}}: CS1 maint: postscript (link)