From Wikipedia, the free encyclopedia
58 Leonis
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]
Distance360 ± 8  ly
(110 ± 2  pc)
Absolute magnitude (MV)−1.04 [4]
Details
Mass1.89 [2]  M
Luminosity182 [2]  L
Surface gravity (log g)1.8 [4]  cgs
Temperature4,519±52 [2]  K
Metallicity [Fe/H]−0.16±0.10 [4]  dex
Age1.69 [2]  Gyr
Other designations
58 Leo, BD+04° 2407, FK5 1284, HD 95345, HIP 53807, HR 4291, SAO 118610, CCDM J11006+0337AB [5]
Database references
SIMBAD data

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]

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

  1. ^ 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.
  2. ^ 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.
  3. ^ 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.
  4. ^ 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
  5. ^ "58 Leo". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2018-03-01.
  6. ^ 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.
  7. ^ Williams, P. M. (February 1971), "Abundances in five newly-discovered BA II stars", The Observatory, 91: 37–39, Bibcode: 1971Obs....91...37W.
  8. ^ 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