Pi Leonis

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π Leonis
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]
Spectral type M2 III[3]
U−B color index +1.88[2]
B−V color index +1.60[2]
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)
Radius 56[5] R
Luminosity 656[6] L
Temperature 3,829[6] K
Other designations
π Leo, 29 Leo, BD+08° 2301, HD 86663, HIP 49029, HR 3950, SAO 118044.[7]

Pi Leonis (π Leo) is a star in the zodiac constellation Leo. It is visible to the naked eye with an apparent visual magnitude of 4.70,[2] and is located some 410 light years from the Sun. This is an evolved, red giant star with a stellar classification of M2 III.[3] It has 56 times the Sun's radius, and shines with 656 times the luminosity of the Sun from an expanded outer atmosphere that has an effective temperature of 3,829 K.[6] According to the General Catalogue of Variable Stars, it is a suspected variable star with a maximum magnitude of 4.67.[8]


  1. ^ a b c d e van Leeuwen, F. (2007), "Validation of the new Hipparcos reduction", Astronomy and Astrophysics, 474 (2): 653–664, arXiv:0708.1752Freely accessible, Bibcode:2007A&A...474..653V, doi:10.1051/0004-6361:20078357. 
  2. ^ a b c d Mermilliod, J.-C. (1986), Compilation of Eggen's UBV data, transformed to UBV (unpublished), SIMBAD, Bibcode:1986EgUBV........0M. 
  3. ^ 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. 
  4. ^ 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:0901.0934Freely accessible, Bibcode:2009A&A...498..627F, doi:10.1051/0004-6361/200810698. 
  5. ^ Pasinetti Fracassini, L. E.; et al. (2001), "Catalogue of Apparent Diameters and Absolute Radii of Stars (CADARS) - Third edition - Comments and statistics", Astronomy & Astrophysics, 367: 521–24, arXiv:astro-ph/0012289Freely accessible, Bibcode:2001A&A...367..521P, doi:10.1051/0004-6361:20000451. 
  6. ^ a b c McDonald, I.; et al. (2012), "Fundamental Parameters and Infrared Excesses of Hipparcos Stars", Monthly Notices of the Royal Astronomical Society, 427 (1): 343–57, arXiv:1208.2037Freely accessible, Bibcode:2012MNRAS.427..343M, doi:10.1111/j.1365-2966.2012.21873.x. 
  7. ^ "pi. Leo -- Variable Star", SIMBAD Astronomical Database, Centre de Données astronomiques de Strasbourg, retrieved 2016-09-29. 
  8. ^ 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.