58 Leonis is a possible binary star[6] system in the southern part of the constellation of Leo, near the border with Sextans. It shines with an apparent magnitude of 4.85,[2] making it bright enough to be seen with the naked eye. An annual parallax shift of 9.05±0.20 mas yields a distance estimate of 360 light years. It is moving further from the Sun with a heliocentric radial velocity of +6 km/s.[2]
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Leo |
| Right ascension | 11h 00m 33.64811s[1] |
| Declination | +03° 37′ 02.9766″[1] |
| Apparent magnitude (V) | 4.852[2] |
| Characteristics | |
| Spectral type | K0.5 III Fe-0.5[3] |
| B−V color index | 1.163[2] |
| Astrometry | |
| Radial velocity (Rv) | +5.98[2] km/s |
| Proper motion (μ) | RA: +14.82[1] mas/yr Dec.: −16.51[1] mas/yr |
| Parallax (π) | 9.05 ± 0.20 mas[1] |
| Distance | 360 ± 8 ly (110 ± 2 pc) |
| Absolute magnitude (MV) | −1.04[4] |
| Details | |
| Mass | 1.89[2] M☉ |
| Luminosity | 182[2] L☉ |
| Surface gravity (log g) | 1.8[4] cgs |
| Temperature | 4,519±52[2] K |
| Metallicity [Fe/H] | −0.16±0.10[4] dex |
| Age | 1.69[2] Gyr |
| Other designations | |
| Database references | |
| SIMBAD | data |
This orange hued star is an evolved K-type giant with a stellar classification of K0.5 III Fe-0.5,[3] indicating a mild underabundance of iron in its spectrum. It was identified as a barium star by P. M. Williams (1971).[7] These are theorized to be stars that show an enrichment of s-process elements by mass transfer from a now-white dwarf companion when it passed through the asymptotic giant branch stage.[8] MacConnell et al. (1972) classified 58 Leonis as a marginal barium star.[4] De Castro et al. (2016) consider this to be only a probable barium star, because of the low degree of s-process enrichment, and they rejected it from their sample. Rather than having an evolved companion, it may instead have formed from a cloud that was mildly enriched with s-process elements.[4]
References
edit- ^ a b c d e 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 e f g h i Luck, R. Earle (2015), "Abundances in the Local Region. I. G and K Giants", Astronomical Journal, 150 (3), 88, arXiv:1507.01466, Bibcode:2015AJ....150...88L, doi:10.1088/0004-6256/150/3/88, S2CID 118505114.
- ^ a b Keenan, Philip C.; McNeil, Raymond C. (1989), "The Perkins catalog of revised MK types for the cooler stars", Astrophysical Journal Supplement Series, 71: 245, Bibcode:1989ApJS...71..245K, doi:10.1086/191373, S2CID 123149047.
- ^ a b c d e De Castro, D. B.; et al. (2016), "Chemical abundances and kinematics of barium stars", Monthly Notices of the Royal Astronomical Society, 459 (4): 4299, arXiv:1604.03031, Bibcode:2016MNRAS.459.4299D, doi:10.1093/mnras/stw815
- ^ "58 Leo". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2018-03-01.
- ^ 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, S2CID 14878976.
- ^ Williams, P. M. (February 1971), "Abundances in five newly-discovered BA II stars", The Observatory, 91: 37–39, Bibcode:1971Obs....91...37W.
- ^ Bergeat, J.; Knapik, A. (May 1997), "The barium stars in the Hertzsprung-Russel diagram.", Astronomy and Astrophysics, 321: L9, Bibcode:1997A&A...321L...9B.
External links
edit- 58 Leonis in Hipparcos stars in Leo