Astronomy:61 Leonis
| Observation data Equinox J2000.0]] (ICRS) | |
|---|---|
| Constellation | Leo |
| Right ascension | 11h 01m 49.67462s[1] |
| Declination | −02° 29′ 04.5007″[1] |
| Apparent magnitude (V) | 4.73[2] |
| Characteristics | |
| Evolutionary stage | AGB[3] |
| Spectral type | M0 III[4] |
| B−V color index | +1.593±0.059[2] |
| Variable type | suspected[5] |
| Astrometry | |
| Radial velocity (Rv) | −12.7±0.3[6] km/s |
| Proper motion (μ) | RA: +9.76[1] mas/yr Dec.: −35.56[1] mas/yr |
| Parallax (π) | 5.58 ± 0.24[1] mas |
| Distance | 580 ± 30 ly (179 ± 8 pc) |
| Absolute magnitude (MV) | −1.53[2] |
| Details | |
| Radius | 74.5[7] R☉ |
| Luminosity | 1,377.86[2] L☉ |
| Surface gravity (log g) | 1.25±0.23[8] cgs |
| Temperature | 3,864±30[8] K |
| Metallicity [Fe/H] | 0.07±0.07[8] dex |
| Other designations | |
| Database references | |
| SIMBAD | data |
61 Leonis is a possible binary star[10] system in the zodiac constellation of Leo. It is faintly visible to the naked eye, having an apparent visual magnitude of 4.73.[2] The star is moving closer to the Sun with a heliocentric radial velocity of −12.7 km/s.[6] It is located roughly 580 light-years from the Sun, as determined from its annual parallax shift of 5.58 mas.[1]
This is an evolved red giant star with a stellar classification of M0 III[4] that Eggen (1992) listed as being on the asymptotic giant branch (AGB).[3] It is a marginal barium star, showing an enhanced abundance of s-process elements in its outer atmosphere. This material may have been acquired during a previous mass transfer from a now white dwarf companion, or self-enriched by a dredge-up during the AGB process.[11] The measured angular diameter after correctly for limb darkening is 3.87±0.04 mas,[12] which, at the estimated distance of this system yields a physical size of about 74.5 times the radius of the Sun.[7]
61 Leonis is a suspected variable star with apparent magnitude changing between 4.69 and 4.79.[5] The variability was reported in a 1966 photometric survey, but has not been confirmed by more recent photometry.[13]
References
- ↑ 1.0 1.1 1.2 1.3 1.4 1.5 van Leeuwen, F. (2007), "Validation of the new Hipparcos reduction", Astronomy and Astrophysics 474 (2): 653–664, doi:10.1051/0004-6361:20078357, Bibcode: 2007A&A...474..653V.
- ↑ 2.0 2.1 2.2 2.3 2.4 Anderson, E.; Francis, Ch. (2012), "XHIP: An extended hipparcos compilation", Astronomy Letters 38 (5): 331, doi:10.1134/S1063773712050015, Bibcode: 2012AstL...38..331A.
- ↑ 3.0 3.1 Eggen, O. J. (1992), "Asymptotic giant branch stars near the sun", The Astronomical Journal 104: 275, doi:10.1086/116239, Bibcode: 1992AJ....104..275E.
- ↑ 4.0 4.1 Keenan, Philip C.; McNeil, Raymond C. (1989), "The Perkins catalog of revised MK types for the cooler stars", Astrophysical Journal Supplement Series 71: 245, doi:10.1086/191373, Bibcode: 1989ApJS...71..245K
- ↑ 5.0 5.1 Samus, N. N. et al. (2009). "VizieR Online Data Catalog: General Catalogue of Variable Stars (Samus+ 2007-2013)". VizieR On-line Data Catalog: B/GCVS. Originally Published in: 2009yCat....102025S 1. Bibcode: 2009yCat....102025S.
- ↑ 6.0 6.1 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.
- ↑ 7.0 7.1 Lang, Kenneth R. (2006), Astrophysical formulae, Astronomy and astrophysics library, 1 (3rd ed.), Birkhäuser, ISBN 3-540-29692-1, https://books.google.com/books?id=OvTjLcQ4MCQC&pg=PA41. The radius (R*) is given by:
- [math]\displaystyle{ \begin{align} 2\cdot R_* & = \frac{(179\cdot 3.87\cdot 10^{-3})\ \text{AU}}{0.0046491\ \text{AU}/R_{\bigodot}} \\ & \approx 149\cdot R_{\bigodot} \end{align} }[/math]
- ↑ 8.0 8.1 8.2 Prugniel, Ph. et al. (2011), "The atmospheric parameters and spectral interpolator for the MILES stars", Astronomy & Astrophysics 531: A165, doi:10.1051/0004-6361/201116769, Bibcode: 2011A&A...531A.165P
- ↑ "61 Leo". SIMBAD. Centre de données astronomiques de Strasbourg. http://simbad.u-strasbg.fr/simbad/sim-basic?Ident=61+Leo.
- ↑ 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.
- ↑ Gomez, A. E. et al. (1997), "Absolute magnitudes and kinematics of barium stars", Astronomy and Astrophysics 319: 881, Bibcode: 1997A&A...319..881G.
- ↑ Richichi, A. et al. (February 2005), "CHARM2: An updated Catalog of High Angular Resolution Measurements", Astronomy and Astrophysics 431 (2): 773–777, doi:10.1051/0004-6361:20042039, Bibcode: 2005A&A...431..773R
- ↑ A. W. J. Cousins (1966). "Fabry photometry of bright southern stars". Royal Greenwich Observatory Bulletins 122: 59. Bibcode: 1966RGOB..122...59C.
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