Astronomy:64 Eridani

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Short description: Single, yellow-white hued star in the constellation Eridanus
64 Eridani
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A light curve for S Eridani, adapted from Koen and Eyer (2002)[1]
Observation data
Equinox J2000.0]] (ICRS)
Constellation Eridanus[2]
Right ascension  04h 59m 55.73680s[3]
Declination −12° 32′ 14.7004″[3]
Apparent magnitude (V) 4.77 – 4.79[4]
Characteristics
Evolutionary stage subgiant[5]
Spectral type F0 V[6]
B−V color index 0.266[7]
Variable type δ Sct[8][4]
Astrometry
Radial velocity (Rv)−8.9±4.2[9] km/s
Proper motion (μ) RA: +39.894[3] mas/yr
Dec.: −87.358[3] mas/yr
Parallax (π)11.5441 ± 0.0851[3] mas
Distance283 ± 2 ly
(86.6 ± 0.6 pc)
Absolute magnitude (MV)+0.03[2]
Details
Mass2.33[10] M
Radius5.22[11] R
Luminosity65[11] L
Surface gravity (log g)3.37[10] cgs
Temperature7,346±250[10] K
Rotational velocity (v sin i)212[12] km/s
Age756[10] Myr
Other designations
64 Eri, S Eri, BD−12°1047, HD 32045, HIP 23231, HR 1611, SAO 150064[13]
Database references
SIMBADdata

64 Eridani is a single,[14] 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 4.8.[7] The annual parallax shift is measured at 12.01 mas, which equates to a distance of about 283 light years.[3] In addition to its proper motion, it is moving closer to the Sun with a radial velocity of around −9 km/s.[9]

This is an F-type star with a stellar classification of F0 V.[6] It is catalogued a low amplitude Delta Scuti variable with a primary period of 0.273 days.[8] It was originally classified, tentatively, as an RR Lyrae variable of type 'c'.[15]

64 Eridani is spinning rapidly with a projected rotational velocity of 212 km/s.[12] This is giving the star an oblate shape with an equatorial bulge; its equatorial radius is 8% larger than its polar radius.[16] The star is an estimated 756 million years old with 2.3 times the mass of the Sun.[10] It is radiating 65 times the Sun's luminosity[11] from its photosphere at an effective temperature of roughly 7,346 K.[10]

References

  1. Koen, Chris; Eyer, Laurent (March 2002). "New periodic variables from the Hipparcos epoch photometry". Monthly Notices of the Royal Astronomical Society 331 (1): 45–59. doi:10.1046/j.1365-8711.2002.05150.x. Bibcode2002MNRAS.331...45K. 
  2. 2.0 2.1 Anderson, E.; Francis, Ch. (2012). "XHIP: An extended hipparcos compilation". Astronomy Letters 38 (5): 331. doi:10.1134/S1063773712050015. Bibcode2012AstL...38..331A  XHIP record for this object at VizieR.
  3. 3.0 3.1 3.2 3.3 3.4 3.5 Vallenari, A. et al. (2022). "Gaia Data Release 3. Summary of the content and survey properties". Astronomy & Astrophysics. doi:10.1051/0004-6361/202243940  Gaia DR3 record for this source at VizieR.
  4. 4.0 4.1 "S Eri". AAVSO. https://vsx.aavso.org/index.php?view=detail.top&oid=13983. 
  5. Zorec, J.; Royer, F. (2012). "Rotational velocities of A-type stars. IV. Evolution of rotational velocities". Astronomy and Astrophysics 537: A120. doi:10.1051/0004-6361/201117691. Bibcode2012A&A...537A.120Z. 
  6. 6.0 6.1 Houk, Nancy; Smith-Moore, M. (1978), Michigan catalogue of two-dimensional spectral types for the HD stars, 4, Ann Arbor: Dept. of Astronomy, University of Michigan, Bibcode1988mcts.book.....H. 
  7. 7.0 7.1 Høg, E. et al. (2000), "The Tycho-2 catalogue of the 2.5 million brightest stars", Astronomy and Astrophysics 355: L27, doi:10.1888/0333750888/2862, Bibcode2000A&A...355L..27H. 
  8. 8.0 8.1 Rodríguez, E.; Breger, M. (January 2001), "delta Scuti and related stars: Analysis of the R00 Catalogue", Astronomy and Astrophysics 366: 178–196, doi:10.1051/0004-6361:20000205, Bibcode2001A&A...366..178R. 
  9. 9.0 9.1 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, doi:10.1051/0004-6361/201219219, A61, Bibcode2012A&A...546A..61D. 
  10. 10.0 10.1 10.2 10.3 10.4 10.5 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, doi:10.1088/0004-637X/804/2/146, Bibcode2015ApJ...804..146D. 
  11. 11.0 11.1 11.2 Fetherolf, Tara; Pepper, Joshua; Simpson, Emilie; Kane, Stephen R.; Močnik, Teo; English, John Edward; Antoci, Victoria; Huber, Daniel et al. (2023). "Variability Catalog of Stars Observed during the TESS Prime Mission". The Astrophysical Journal Supplement Series 268 (1): 4. doi:10.3847/1538-4365/acdee5. Bibcode2023ApJS..268....4F. 
  12. 12.0 12.1 Royer, F. et al. (February 2007), "Rotational velocities of A-type stars. III. Velocity distributions", Astronomy and Astrophysics 463 (2): 671–682, doi:10.1051/0004-6361:20065224, Bibcode2007A&A...463..671R. 
  13. "64 Eri". SIMBAD. Centre de données astronomiques de Strasbourg. http://simbad.u-strasbg.fr/simbad/sim-basic?Ident=64+Eri. 
  14. 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, doi:10.1111/j.1365-2966.2008.13596.x, Bibcode2008MNRAS.389..869E. 
  15. Samus, N. N. et al. (2017), "General Catalogue of Variable Stars", Astronomy Reports, 5.1 61 (1): 80–88, doi:10.1134/S1063772917010085, Bibcode2017ARep...61...80S, http://www.sai.msu.su/gcvs/gcvs/, retrieved 2019-08-06. 
  16. Belle, G. T. (2012). "Interferometric observations of rapidly rotating stars". The Astronomy and Astrophysics Review 20 (1): 51. doi:10.1007/s00159-012-0051-2. Bibcode2012A&ARv..20...51V.