Eta Leonis
Location of η Leo (circled)
Observation data
Epoch J2000      Equinox J2000
Constellation Leo
Right ascension 10h 07m 19.95186s[1]
Declination 16° 45′ 45.592″[1]
Apparent magnitude (V) 3.486[2]
Characteristics
Spectral type A0 Ib[2]
U−B color index −0.206[2]
B−V color index −0.026[2]
Astrometry
Radial velocity (Rv)1.40[3] km/s
Proper motion (μ) RA: −2.80[1] mas/yr
Dec.: −1.82[1] mas/yr
Parallax (π)2.57 ± 0.16 mas[1]
Distance1,270 ± 80 ly
(390 ± 20 pc)
Absolute magnitude (MV)−5.54[4]
Details
Mass10[5] M☉
Radius47[4] R☉
Luminosity19,000[5] L☉
Surface gravity (log g)2.00[5] cgs
Temperature9,600[2] K
Metallicity−0.04[4]
Rotational velocity (v sin i)2[2] km/s
Age25[5] Myr
Other designations
η Leo, 30 Leonis, HR 3975, BD+17°2171, HD 87737, FK5 379, HIP 49583, SAO 98955, GC 13899
Database references
SIMBADdata

Eta Leonis (η Leo, η Leonis) is a fourth-magnitude star in the constellation Leo, about 1,270 light years away.

Properties

Eta Leonis is a white supergiant with the stellar classification A0Ib. Since 1943, the spectrum of this star has served as one of the stable anchor points by which other stars are classified.[6] Though its apparent magnitude is 3.5, making it a relatively dim star to the naked eye, it is nearly 20,000 times more luminous than the Sun, with an absolute magnitude of -5.60. The Hipparcos astrometric data has estimated the distance of Eta Leonis to be roughly 390 parsecs from Earth, or 1,270 light years away.

Eta Leonis is apparently a multiple star system, but the number of components and their separation is uncertain.[7]

References

  1. 1 2 3 4 5 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.
  2. 1 2 3 4 5 6 Firnstein, M.; Przybilla, N. (2012). "Quantitative spectroscopy of Galactic BA-type supergiants. I. Atmospheric parameters". Astronomy & Astrophysics. 543: A80. arXiv:1207.0308. Bibcode:2012A&A...543A..80F. doi:10.1051/0004-6361/201219034. S2CID 54725386.
  3. ↑ Gontcharov, G. A. (2006). "Pulkovo Compilation of Radial Velocities for 35 495 Hipparcos stars in a common system". Astronomy Letters. 32 (11): 759–771. arXiv:1606.08053. Bibcode:2006AstL...32..759G. doi:10.1134/S1063773706110065. S2CID 119231169.
  4. 1 2 3 Przybilla, N.; Butler, K.; Becker, S. R.; Kudritzki, R. P. (2006). "Quantitative spectroscopy of BA-type supergiants". Astronomy and Astrophysics. 445 (3): 1099. arXiv:astro-ph/0509669. Bibcode:2006A&A...445.1099P. doi:10.1051/0004-6361:20053832. S2CID 118953817.
  5. 1 2 3 4 Tanrıverdi, Taner (2013). "Elemental abundances of the supergiant stars σ Cygnus and η Leonis". New Astronomy. 25: 50. arXiv:1512.04557. Bibcode:2013NewA...25...50T. doi:10.1016/j.newast.2013.03.013. S2CID 118525375.
  6. ↑ Garrison, R. F. (December 1993). "Anchor Points for the MK System of Spectral Classification". Bulletin of the American Astronomical Society. 25: 1319. Bibcode:1993AAS...183.1710G.
  7. ↑ Mason, Brian D. (1996). "ICCD Speckle Observations of Binary Stars.XV.An Investigation of Lunar Occultation Systems". The Astronomical Journal. 112: 2260. Bibcode:1996AJ....112.2260M. doi:10.1086/118179.
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