R Leonis
| Observation data Epoch J2000.0 Equinox J2000.0  | |
|---|---|
| Constellation | Leo | 
| Right ascension | 09h 47m 33.4840s | 
| Declination | +11° 25′ 43.823″ | 
| Apparent magnitude (V) | 4.4 - 11.3 | 
| Characteristics | |
| Spectral type | M6e-M8IIIe-M9.5e | 
| Apparent magnitude (J) | −0.7 | 
| B−V color index | 1.26 | 
| Variable type | Mira variable | 
| Astrometry | |
| Proper motion (μ) |  RA: 6.132 mas/yr  Dec.: −53.097 mas/yr  | 
| Parallax (π) | 14.0566±0.8378 mas | 
| Distance | 372 ly  (114 pc)  | 
| Details | |
| Mass | 0.7 M☉ | 
| Radius | 320 – 350 R☉ | 
| Luminosity | 3,537 L☉ | 
| Temperature | 2,930 – 3,080 K | 
| Other designations | |
| R Leo, AAVSO 0942+11, BD+12°2096, HD 84748, HIP 48036, HR 3882, SAO 98769 | |
| Database references | |
| SIMBAD | data | 
R Leonis is a red giant Mira-type variable star located approximately 370 light years away in the constellation Leo.
The apparent magnitude of R Leonis varies between 4.31 and 11.65 with a period of 312 days. At maximum it can be seen with the naked eye, while at minimum a telescope of at least 7 cm is needed. The star's effective temperature is estimated to be 2,930 – 3,080 kelvins and radius spans 320 solar radii (220,000,000 kilometres; 1.5 astronomical units), roughly Mars's orbital zone.