Astronomy:64 Eridani
| 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 |
| Distance | 283 ± 2 ly (86.6 ± 0.6 pc) |
| Absolute magnitude (MV) | +0.03[2] |
| Details | |
| Mass | 2.33[10] M☉ |
| Radius | 5.22[11] R☉ |
| Luminosity | 65[11] L☉ |
| Surface gravity (log g) | 3.37[10] cgs |
| Temperature | 7,346±250[10] K |
| Rotational velocity (v sin i) | 212[12] km/s |
| Age | 756[10] Myr |
| Other designations | |
| Database references | |
| SIMBAD | data |
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
- ↑ 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. Bibcode: 2002MNRAS.331...45K.
- ↑ 2.0 2.1 Anderson, E.; Francis, Ch. (2012). "XHIP: An extended hipparcos compilation". Astronomy Letters 38 (5): 331. doi:10.1134/S1063773712050015. Bibcode: 2012AstL...38..331A XHIP record for this object at VizieR.
- ↑ 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.
- ↑ 4.0 4.1 "S Eri". AAVSO. https://vsx.aavso.org/index.php?view=detail.top&oid=13983.
- ↑ 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. Bibcode: 2012A&A...537A.120Z.
- ↑ 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, Bibcode: 1988mcts.book.....H.
- ↑ 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, Bibcode: 2000A&A...355L..27H.
- ↑ 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, Bibcode: 2001A&A...366..178R.
- ↑ 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, Bibcode: 2012A&A...546A..61D.
- ↑ 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, Bibcode: 2015ApJ...804..146D.
- ↑ 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. Bibcode: 2023ApJS..268....4F.
- ↑ 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, Bibcode: 2007A&A...463..671R.
- ↑ "64 Eri". SIMBAD. Centre de données astronomiques de Strasbourg. http://simbad.u-strasbg.fr/simbad/sim-basic?Ident=64+Eri.
- ↑ 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, Bibcode: 2008MNRAS.389..869E.
- ↑ Samus, N. N. et al. (2017), "General Catalogue of Variable Stars", Astronomy Reports, 5.1 61 (1): 80–88, doi:10.1134/S1063772917010085, Bibcode: 2017ARep...61...80S, http://www.sai.msu.su/gcvs/gcvs/, retrieved 2019-08-06.
- ↑ 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. Bibcode: 2012A&ARv..20...51V.
