Gliese 581
Gliese 581 (/ˈɡliːzə/) is a red dwarf star of spectral type M3V at the center of the Gliese 581 planetary system, about 20.5 light years away from Earth in the Libra constellation. Its estimated mass is about a third of that of the Sun, and it is the 101st closest known star system to the Sun. Gliese 581 is one of the oldest, least active M dwarfs known. Its low stellar activity improves the likelihood of its planets retaining significant atmospheres, and lessens the sterilizing impact of stellar flares.
Gliese 581 Location of Gliese 581 in the constellation Libra | |
| Observation data Epoch J2000.0 Equinox J2000.0 | |
|---|---|
| Constellation | Libra |
| Right ascension | 15h 19m 26.82694s |
| Declination | −07° 43′ 20.1895″ |
| Apparent magnitude (V) | 10.56 to 10.58 |
| Characteristics | |
| Evolutionary stage | Main sequence |
| Spectral type | M3V |
| B−V color index | 1.61 |
| Variable type | BY Dra |
| Astrometry | |
| Radial velocity (Rv) | −9.75±0.16 km/s |
| Proper motion (μ) | RA: −1221.278±0.037 mas/yr Dec.: −97.229±0.027 mas/yr |
| Parallax (π) | 158.7183 ± 0.0301 mas |
| Distance | 20.549 ± 0.004 ly (6.300 ± 0.001 pc) |
| Absolute magnitude (MV) | 11.6 |
| Details | |
| Mass | 0.307±0.007 M☉ |
| Radius | 0.310±0.008 R☉ |
| Luminosity (bolometric) | 0.01192±0.00010 L☉ |
| Luminosity (visual, LV) | 0.002 L☉ |
| Surface gravity (log g) | 4.92±0.10 cgs |
| Temperature | 3,424+43 −42 K |
| Metallicity [Fe/H] | −0.33 ± 0.12 dex |
| Rotation | 132.5±6.3 d |
| Age | 8+3 −1 Gyr |
| Other designations | |
| Database references | |
| SIMBAD | The star |
| e | |
| b | |
| c | |
| d | |
| f (artifact) | |
| g | |
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