Kappa Eridani
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) | ±0.5 +25.5[4] km/s |
Proper motion (μ) | RA: +19.32[1] mas/yr Dec.: −5.54[1] mas/yr |
Parallax (π) | 6.42 ± 0.15[1] mas |
Distance | 510 ± 10 ly (156 ± 4 pc) |
Details[3] | |
Mass | ±0.8 5.0 M☉ |
Radius | 6[5][6] R☉ |
Luminosity | 1,175 L☉ |
Surface gravity (log g) | ±0.1 3.5 cgs |
Temperature | ±400 14,700 K |
Metallicity [Fe/H] | ±0.06 0.02[7] dex |
Rotational velocity (v sin i) | ±8 10 km/s |
Age | 93 Myr |
Other designations | |
Kappa Eridani (κ Eri) 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.
This appears to be an evolving B-type subgiant star with a stellar classification of B7 IV.[3] The measured angular diameter is ±0.008 mas. 0.346[7] At an estimated distance of Kappa Eridani, this yields a physical size of about six times the radius of the Sun.[5] 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
- 1 2 3 4 5 6 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.
- 1 2 3 4 Johnson, H. L.; et al. (1966), "UBVRIJKL photometry of the bright stars", Communications of the Lunar and Planetary Laboratory, 4 (99), Bibcode:1966CoLPL...4...99J.
- 1 2 3 4 Levenhagen, R. S.; Leister, N. V. (2006), "Spectroscopic Analysis of Southern B and Be Stars", Monthly Notices of the Royal Astronomical Society, 371: 252–62, arXiv:astro-ph/0606149, Bibcode:2006MNRAS.371..252L, doi:10.1111/j.1365-2966.2006.10655.x.
- ↑ 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.
- 1 2 Lang, Kenneth R. (2006), Astrophysical formulae, Astronomy and astrophysics library, 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: 521–24, arXiv:astro-ph/0012289, Bibcode:2001A&A...367..521P, doi:10.1051/0004-6361:20000451.
- 1 2 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 -- Star", SIMBAD Astronomical Database, Centre de Données astronomiques de Strasbourg, retrieved 2016-10-30.