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Pi Leonis 
Summary
Pi Leonis, Latinised from π Leonis, is a single[11] 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.[12]
| 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 mas[1] |
| Distance | 410 ± 10 ly (125 ± 4 pc) |
| Absolute magnitude (MV) | −0.79[5] |
| Details | |
| Mass | 1.64[6] M☉ |
| Radius | 84.7[6] R☉ |
| Luminosity | 1,077±73[7] L☉ |
| Surface gravity (log g) | 1.028[8] cgs |
| Temperature | 3,757[8] K |
| Metallicity [Fe/H] | +0.447[8] dex |
| Age | 550[9] Myr |
| 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 3,757 K. According to the General Catalogue of Variable Stars, it is a suspected variable star with a maximum magnitude of 4.67.[13] The age of Pi Leonis is estimated at 550 million years.[9]
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- ^ a b c d Mermilliod, J.-C. (1986), "Compilation of Eggen's UBV data, transformed to UBV (unpublished)", Catalogue of Eggen's UBV Data, SIMBAD, Bibcode:1986EgUBV........0M.
- ^ a b 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.
- ^ a b 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, S2CID 18739721.
- ^ 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, S2CID 119257644.
- ^ a b Kervella, Pierre; Arenou, Frédéric; Thévenin, Frédéric (2022), "Stellar and substellar companions from Gaia EDR3. Proper-motion anomaly and resolved common proper-motion pairs", Astronomy and Astrophysics, 657: 657, arXiv:2109.10912, Bibcode:2022A&A...657A...7K, doi:10.1051/0004-6361/202142146, S2CID 237605138.
- ^ 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.
- ^ a b c Cardiel, Nicolás; Zamorano, Jaime; Bará, Salvador; Sánchez De Miguel, Alejandro; Cabello, Cristina; Gallego, Jesús; García, Lucía; González, Rafael; Izquierdo, Jaime; Pascual, Sergio; Robles, José; Sánchez, Ainhoa; Tapia, Carlos (2021), "Synthetic RGB photometry of bright stars: Definition of the standard photometric system and UCM library of spectrophotometric spectra", Monthly Notices of the Royal Astronomical Society, 504 (3): 3730, arXiv:2103.17009, Bibcode:2021MNRAS.504.3730C, doi:10.1093/mnras/stab997.
- ^ a b Guide, Universe (2015-01-25). "Pi Leonis Star Facts (Type, Distance, Magnitude, Colour, Luminosity, Location & more)". Universe Guide. Retrieved 2022-05-01.
- ^ "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, S2CID 14878976.
- ^ 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.