Pi Leonis
Pi Leonis, Latinized from π Leonis, is a single[9] star in the zodiac constellation Leo. It is a red hued star that is visible to the naked eye with an apparent visual magnitude of 4.70.[2] This object is located at a distance of some 410 light years from the Sun based on parallax, and is drifting further away with a radial velocity of +22 km/s.[4] Because the star lies near the ecliptic it is subject to occultations by the Moon.[10]
| Observation data Epoch J2000.0 Equinox J2000.0 (ICRS) | |
|---|---|
| Constellation | Leo |
| Right ascension | 10h 00m 12.80589s[1] |
| Declination | +08° 02′ 39.2032″[1] |
| Apparent magnitude (V) | 4.70[2] |
| Characteristics | |
| Spectral type | M2 III[3] |
| U−B color index | +1.88[2] |
| B−V color index | +1.60[2] |
| Astrometry | |
| Radial velocity (Rv) | 22.36±0.29[4] km/s |
| Proper motion (μ) | RA: −31.41[1] mas/yr Dec.: −22.15[1] mas/yr |
| Parallax (π) | 8.03 ± 0.29[1] mas |
| Distance | 410 ± 10 ly (125 ± 4 pc) |
| Absolute magnitude (MV) | −0.79[5] |
| Details | |
| Radius | 70+6 −5[6] R☉ |
| Luminosity | 1,077±73[6] L☉ |
| Surface gravity (log g) | 2.95[7] cgs |
| Temperature | 3,956+158 −159[6] K |
| Metallicity [Fe/H] | 0.104[7] dex |
| Other designations | |
| Database references | |
| SIMBAD | data |
This is an evolved, red giant star with a stellar classification of M2 III.[3] With the supply of hydrogen at its core exhausted, it has expanded to 70 times the Sun's radius. The star shines with 1,077 times the luminosity of the Sun from an expanded outer atmosphere that has an effective temperature of 3,956 K.[6] According to the General Catalogue of Variable Stars, it is a suspected variable star with a maximum magnitude of 4.67.[11]
References
- 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.
- Mermilliod, J.-C. (1986), Compilation of Eggen's UBV data, transformed to UBV (unpublished), SIMBAD, Bibcode:1986EgUBV........0M.
- Morgan, W. W.; Keenan, P. C. (1973), "Spectral Classification", Annual Review of Astronomy and Astrophysics, 11: 29, Bibcode:1973ARA&A..11...29M, doi:10.1146/annurev.aa.11.090173.000333.
- Famaey, B.; et al. (2009), "Spectroscopic binaries among Hipparcos M giants,. I. Data, orbits, and intrinsic variations", Astronomy and Astrophysics, 498 (2): 627–640, arXiv:0901.0934, Bibcode:2009A&A...498..627F, doi:10.1051/0004-6361/200810698.
- 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.
- Brown, A. G. A.; et al. (Gaia collaboration) (August 2018). "Gaia Data Release 2: Summary of the contents and survey properties". Astronomy & Astrophysics. 616. A1. arXiv:1804.09365. Bibcode:2018A&A...616A...1G. doi:10.1051/0004-6361/201833051. Gaia DR2 record for this source at VizieR.
- Tabernero, H. M.; Montes, D.; González Hernández, J. I. (November 2012), "Chemically tagging the Hyades Supercluster. A homogeneous sample of F6-K4 kinematically selected northern stars", Astronomy & Astrophysics, 547: 15, arXiv:1205.4879, Bibcode:2012A&A...547A..13T, doi:10.1051/0004-6361/201117506, A13.
- "pi. Leo -- Variable Star", SIMBAD Astronomical Database, Centre de Données astronomiques de Strasbourg, retrieved 2016-09-29.
- 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.
- White, Nathaniel M.; Feierman, Barry H. (September 1987), "A Catalog of Stellar Angular Diameters Measured by Lunar Occultation", Astronomical Journal, 94: 751, Bibcode:1987AJ.....94..751W, doi:10.1086/114513.
- Samus, N. N.; Durlevich, O. V.; et al. (2007), Combined General Catalogue of Variable Stars (GCVS4.2), retrieved 2016-09-30. VizieR On-line Data Catalog: B/gcvs.