Omicron Leonis

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Omicron Leonis
Leo constellation map.png
Omicron Leonis is located to the lower far right on this map of the constellation.
Observation data
Epoch J2000.0      Equinox J2000.0
Constellation Leo
Right ascension 09h 41m 09.03s
Declination +09° 53' 32.30"
Apparent magnitude (V) +3.52[1]
Spectral type F8-G0III/A7m[2]
U−B color index 0.21[1]
B−V color index 0.49[1]
Proper motion (μ) RA: -143.20[3] mas/yr
Dec.: -37.20[3] mas/yr
Parallax (π) 25.03[3] ± 0.22 mas
Distance 135 ly
(41.4±0.1[4] pc)
Period (P) 14.498064 ± 0.000009 days
Semi-major axis (a) 4.46 ± 0.01 mas
Eccentricity (e) 0
Inclination (i) 57.6 ± 0.1°
Longitude of the node (Ω) 191.4 ± 0.1°
Periastron epoch (T) TJD 10629.831 ± 0.003
Mass 2.12/1.87 ± 0.01[4] M
Radius 5.9±0.5/2.2±0.3[4] R
Luminosity 39.4±2.4/15.4±1.0 [4] L
Temperature 6,000±200/7,600±400[4] K
Age 8 × 108(estimate)[4] years
Other designations
14 Leo, HR 3852, BD+10 2044, HD 83808/83809, SAO 98709, FK5 365, HIP 47508.
Database references

Omicron Leonis (ο Leonis, abbreviated Omicron Leo, ο Leo), also named Subra,[5] is a binary star in the constellation of Leo, west of Regulus, some 130 light years from the Sun, where it marks one of the lion's forepaws.


ο Leonis (Latinised to Omicron Leonis) is the star's Bayer designation.

It bore the traditional name Subra.[6] In 2016, the International Astronomical Union organized a Working Group on Star Names (WGSN)[7] to catalogue and standardize proper names for stars. The WGSN approved the name Subra for this star on 12 September 2016 and it is now so entered in the IAU Catalog of Star Names.[5]


The primary is given the type F8-G0III giant and the secondary (Subra-B) is type A7m dwarf.[4] Their combined apparent magnitude is +3.52.


  1. ^ a b c Ducati, J. R. (2002). "VizieR Online Data Catalog: Catalogue of Stellar Photometry in Johnson's 11-color system". CDS/ADC Collection of Electronic Catalogues. 2237: 0. Bibcode:2002yCat.2237....0D. 
  2. ^ Ginestet, N.; Carquillat, J. M. (2002). "Spectral Classification of the Hot Components of a Large Sample of Stars with Composite Spectra, and Implication for the Absolute Magnitudes of the Cool Supergiant Components". The Astrophysical Journal Supplement Series. 143 (2): 513. Bibcode:2002ApJS..143..513G. doi:10.1086/342942. 
  3. ^ a b c 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. 
  4. ^ a b c d e f g h Hummel, C. A.; Carquillat, J. -M.; Ginestet, N.; Griffin, R. F.; Boden, A. F.; Hajian, A. R.; Mozurkewich, D.; Nordgren, T. E. (2001). "Orbital and Stellar Parameters of Omicron Leonis from Spectroscopy and Interferometry". The Astronomical Journal. 121 (3): 1623. Bibcode:2001AJ....121.1623H. doi:10.1086/319391. 
  5. ^ a b "IAU Catalog of Star Names". Retrieved 28 July 2016. 
  6. ^ Jim Kaler's website: (online 6th Sep 2015)
  7. ^ IAU Working Group on Star Names (WGSN), International Astronomical Union, retrieved 22 May 2016. 

External links[edit]