59 Leonis

59 Leonis, or c Leonis, is a single[9] white-hued star in the southern part of the constellation of Leo. It is north of 58 Leonis, south of Chi Leonis, and well east of the bright star Regulus. Its apparent visual magnitude is 4.98, so it is dimly visible to the naked eye, 0.21 degree south of the ecliptic.[2] The annual parallax shift as seen from Earth's orbit is 21.57±0.26 mas,[1] giving a distance estimate of about 151 light years. The star is moving closer to the Sun with a heliocentric radial velocity of −12 km/s.[5]

59 Leonis
Observation data
Epoch J2000      Equinox J2000
Constellation Leo
Right ascension 11h 00m 44.80142s[1]
Declination +06° 06′ 05.2093″[1]
Apparent magnitude (V) 4.98[2]
Characteristics
Spectral type A5 III[3] or A6 IV[4]
B−V color index 0.166±0.005[2]
Astrometry
Radial velocity (Rv)−11.7±1.3[5] km/s
Proper motion (μ) RA: −52.73[1] mas/yr
Dec.: −23.23[1] mas/yr
Parallax (π)21.57 ± 0.26[1] mas
Distance151 ± 2 ly
(46.4 ± 0.6 pc)
Absolute magnitude (MV)1.65[2]
Details
Mass1.73[6] M☉
Luminosity18.27[2] L☉
Surface gravity (log g)4.15±0.14[6] cgs
Temperature8,277±281[6] K
Rotational velocity (v sin i)82[7] km/s
Age332[6] Myr
Other designations
c Leo, 59 Leo, BD+06° 2384, HD 95382, HIP 53824, HR 4294, SAO 118615, WDS J11007+0606A[8]
Database references
SIMBADdata

Cowley et al. (1969) assigned 59 Leonis a stellar classification of A5 III,[3] matching the spectrum of an A-type giant star, but Gray and Garrison (1989) found a class of A6 IV,[4] suggesting it is a subgiant star. Hauck (1986) noted that the star is classified as a giant, but the colors match a dwarf star and it had been previously classified as F3 V.[10] It is an estimated 332[6] million years old with a high rate of spin, showing a projected rotational velocity of 82 km/s.[7] The star has around 1.73[6] times the mass of the Sun and is radiating 18[2] times the Sun's luminosity from its photosphere at an effective temperature of about 8,277 K.[6]

References
  1. 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.
  2. 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.
  3. Cowley, A.; et al. (April 1969), "A study of the bright A stars. I. A catalogue of spectral classifications", Astronomical Journal, 74: 375–406, Bibcode:1969AJ.....74..375C, doi:10.1086/110819
  4. Gray, R. O.; Garrison, R. F. (July 1989), "The Late A-Type Stars: Refined MK Classification, Confrontation with Stroemgren Photometry, and the Effects of Rotation", Astrophysical Journal Supplement, 70: 623, Bibcode:1989ApJS...70..623G, doi:10.1086/191349.
  5. 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, arXiv:1208.3048, Bibcode:2012A&A...546A..61D, doi:10.1051/0004-6361/201219219, A61.
  6. David, Trevor J.; Hillenbrand, Lynne A. (2015), "The Ages of Early-Type Stars: Strömgren Photometric Methods Calibrated, Validated, Tested, and Applied to Hosts and Prospective Hosts of Directly Imaged Exoplanets", The Astrophysical Journal, 804 (2): 146, arXiv:1501.03154, Bibcode:2015ApJ...804..146D, doi:10.1088/0004-637X/804/2/146.
  7. Royer, F.; et al. (October 2002), "Rotational velocities of A-type stars in the northern hemisphere. II. Measurement of v sin i", Astronomy and Astrophysics, 393: 897–911, arXiv:astro-ph/0205255, Bibcode:2002A&A...393..897R, doi:10.1051/0004-6361:20020943.
  8. "59 Leo". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2018-03-01.
  9. De Rosa, R. J.; et al. (2014), "The VAST Survey - III. The multiplicity of A-type stars within 75 pc", Monthly Notices of the Royal Astronomical Society, 437 (2): 1216, arXiv:1311.7141, Bibcode:2014MNRAS.437.1216D, doi:10.1093/mnras/stt1932.
  10. Hauck, B. (February 1986), "Metallicism among A and F giant stars", Astronomy and Astrophysics, 155: 371−379, Bibcode:1986A&A...155..371H.
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