Omicron Leonis
| Observation data Epoch J2000.0 Equinox J2000.0  | |
|---|---|
| Constellation | Leo | 
| Right ascension | 09h 41m 09.032s | 
| Declination | +09° 53′ 32.31″ | 
| Apparent magnitude (V) | +3.52 | 
| Characteristics | |
| Spectral type | F8-G0III + A7m | 
| U−B color index | 0.21 | 
| B−V color index | 0.49 | 
| Astrometry | |
| Proper motion (μ) |  RA: -143.20 mas/yr  Dec.: -37.20 mas/yr  | 
| Parallax (π) | 24.412±0.081 mas | 
| Distance | 133.53±0.45 ly  (40.96±0.14 pc)  | 
| Absolute magnitude (MV) | +0.51 | 
| Orbit | |
| Primary | Aa | 
| Companion | Ab | 
| Period (P) | 14.498068(6) days | 
| Semi-major axis (a) | 0.1834±0.0007 AU | 
| Eccentricity (e) | 0.0007±0.0004 | 
| Inclination (i) | 57.8±0.2° | 
| Longitude of the node (Ω) | 191.6±0.1° | 
| Periastron epoch (T) | 2450623.9(9) days | 
| Argument of periastron (ω) (secondary)  | 214±22° | 
| Semi-amplitude (K1) (primary)  | 54.75±0.02 km/s | 
| Semi-amplitude (K2) (secondary)  | 61.66±0.02 km/s | 
| Details | |
| ο Leo Aa | |
| Mass | 2.074±0.013 M☉ | 
| Radius | 5.73±0.34 R☉ | 
| Luminosity | 41.1+5.8 −5.1 L☉  | 
| Temperature | 6,107±93 K | 
| Metallicity [Fe/H] | 0.11±0.10 dex | 
| Age | 1.06±0.03 Gyr | 
| ο Leo Ab | |
| Mass | 1.841±0.011 M☉ | 
| Radius | 2.43±0.35 R☉ | 
| Luminosity | 17.8+5.7 −4.3 L☉  | 
| Temperature | 7,600±200 K | 
| Metallicity [Fe/H] | 0.11±0.10 dex | 
| Age | 1.06±0.03 Gyr | 
| Other designations | |
| Subra, ο Leo, 14 Leo, BD+10 2044, FK5 365, HD 83808/83809, HIP 47508, HR 3852, SAO 98709 | |
| Database references | |
| SIMBAD | data | 
Omicron Leonis (ο Leonis, abbreviated Omicron Leo, ο Leo) is a multiple star system in the constellation of Leo, west of Regulus, some 130 light-years from the Sun, where it marks one of the lion's forepaws. The position of this system near the ecliptic means it is subject to lunar occultation.
It consists of a binary pair, designated Omicron Leonis A and an optical companion, Omicron Leonis B. A's two components are themselves designated Omicron Leonis Aa (officially named Subra /ˈsuːbrə/, the traditional name for the system) and Ab.