Ross 128
| Location of Ross 128 in the constellation Virgo | |
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Virgo | 
| Right ascension | 11h 47m 44.39727s | 
| Declination | +00° 48′ 16.4003″ | 
| Apparent magnitude (V) | 11.13 | 
| Characteristics | |
| Evolutionary stage | Main sequence | 
| Spectral type | M4V | 
| U−B color index | +2.685 | 
| B−V color index | +1.59 | 
| Variable type | Flare star | 
| Astrometry | |
| Radial velocity (Rv) | −31.0 km/s | 
| Proper motion (μ) | RA: 607.299(34) mas/yr Dec.: −1223.028(23) mas/yr | 
| Parallax (π) | 296.3053±0.0302 mas | 
| Distance | 11.007 ± 0.001 ly (3.3749 ± 0.0003 pc) | 
| Absolute magnitude (MV) | 13.53 | 
| Details | |
| Mass | 0.176±0.004 M☉ | 
| Radius | 0.198±0.007 R☉ | 
| Luminosity (bolometric) | 0.00366 ± 0.00005 L☉ | 
| Surface gravity (log g) | 3.40 cgs | 
| Temperature | 3,189+55 −53 K | 
| Metallicity [Fe/H] | −0.02±0.08 dex | 
| Rotation | 101–223 days | 
| Rotational velocity (v sin i) | 2.1±1.0 km/s | 
| Age | 5.0 Gyr | 
| Other designations | |
| FI Vir, GJ 447, HIP 57548, G 10-50, LFT 852, LHS 315, LSPM J1147+0048, LTT 13240, PLX 2730, Ross 128, Vyssotsky 286 | |
| Database references | |
| SIMBAD | data | 
| Exoplanet Archive | data | 
Ross 128 is a red dwarf star in the equatorial zodiac constellation of Virgo, near β Virginis. The apparent magnitude of Ross 128 is 11.13, which is too faint to be seen with the unaided eye. Based upon parallax measurements, the distance of this star from Earth is 11.007 light-years (3.375 parsecs), making it the twelfth closest stellar system to the Solar System. It was first cataloged in 1926 by American astronomer Frank Elmore Ross.