Summary
Kappa Eridani, Latinized from κ Eridani, is a solitary star in the constellation Eridanus. With an apparent visual magnitude of 4.25,[2] it is bright enough to be visible to the naked eye on a dark night. Based upon an annual parallax shift of 0.00642 arc seconds,[1] it is roughly 510 light years distant from the Sun.
| Observation data Epoch J2000.0 Equinox J2000.0 (ICRS) | |
|---|---|
| Constellation | Eridanus |
| Right ascension | 02h 26m 59.12177s[1] |
| Declination | −47° 42′ 13.8247″[1] |
| Apparent magnitude (V) | 4.25[2] |
| Characteristics | |
| Spectral type | B7 IV[3] |
| U−B color index | −0.50[2] |
| B−V color index | −0.14[2] |
| Astrometry | |
| Radial velocity (Rv) | +25.5±0.5[4] km/s |
| Proper motion (μ) | RA: +19.32[1] mas/yr Dec.: −5.54[1] mas/yr |
| Parallax (π) | 6.42 ± 0.15 mas[1] |
| Distance | 510 ± 10 ly (156 ± 4 pc) |
| Absolute magnitude (MV) | −1.72[5] |
| Details[3] | |
| Mass | 5.0±0.8 M☉ |
| Radius | 6[6][7] R☉ |
| Luminosity | 1,175 L☉ |
| Surface gravity (log g) | 3.5±0.1 cgs |
| Temperature | 14,700±400 K |
| Metallicity [Fe/H] | 0.02±0.06[8] dex |
| Rotational velocity (v sin i) | 10±8 km/s |
| Age | 93 Myr |
| Other designations | |
| Database references | |
| SIMBAD | data |
This appears to be an evolving B-type subgiant star with a stellar classification of B7 IV.[3] The measured angular diameter is 0.346±0.008 mas.[8] At an estimated distance of Kappa Eridani, this yields a physical size of about six times the radius of the Sun.[6] It has five times the Sun's mass, and radiates 1,175 times the solar luminosity from its outer atmosphere at an effective temperature of 14,700 K. Kappa Eridani is spinning with a projected rotational velocity of 10 km/s and is around 93 million years old.[3]
References edit
- ^ a b c d e f van Leeuwen, F. (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, S2CID 18759600.
- ^ a b c d Johnson, H. L.; et al. (1966), "UBVRIJKL photometry of the bright stars", Communications of the Lunar and Planetary Laboratory, 4 (99): 99, Bibcode:1966CoLPL...4...99J.
- ^ a b c d Levenhagen, R. S.; Leister, N. V. (2006), "Spectroscopic Analysis of Southern B and Be Stars", Monthly Notices of the Royal Astronomical Society, 371 (1): 252–62, arXiv:astro-ph/0606149, Bibcode:2006MNRAS.371..252L, doi:10.1111/j.1365-2966.2006.10655.x, S2CID 16492030.
- ^ 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 Lang, Kenneth R. (2006), Astrophysical formulae, Astronomy and astrophysics library, vol. 1 (3rd ed.), Birkhäuser, ISBN 3-540-29692-1.
The radius (R*) is given by: - ^ Pasinetti Fracassini, L. E.; et al. (2001), "Catalogue of Apparent Diameters and Absolute Radii of Stars (CADARS) - Third edition - Comments and statistics", Astronomy & Astrophysics, 367 (2): 521–24, arXiv:astro-ph/0012289, Bibcode:2001A&A...367..521P, doi:10.1051/0004-6361:20000451, S2CID 425754.
- ^ a b Niemczura, E. (June 2003), "Metallicities of the SPB stars from the IUE ultraviolet spectra", Astronomy and Astrophysics, 404 (2): 689–700, Bibcode:2003A&A...404..689N, doi:10.1051/0004-6361:20030546.
- ^ "kap Eri". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2016-10-30.
