Gliese 229
Gliese 229 Location of Gliese 229 in the constellation Lepus | |
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Lepus |
| Right ascension | 06h 10m 34.61494s |
| Declination | −21° 51′ 52.6564″ |
| Apparent magnitude (V) | 8.12 |
| Characteristics | |
| Red dwarf | |
| Spectral type | M1Ve |
| U−B color index | +1.222 |
| B−V color index | +1.478 |
| Variable type | Flare star |
| Brown dwarfs | |
| Spectral type | T7+T8 |
| Astrometry | |
| A | |
| Radial velocity (Rv) | +4.23±0.12 km/s |
| Proper motion (μ) | RA: −135.692(11) mas/yr Dec.: −719.178(17) mas/yr |
| Parallax (π) | 173.5740±0.0170 mas |
| Distance | 18.791 ± 0.002 ly (5.7612 ± 0.0006 pc) |
| Absolute magnitude (MV) | 9.326 |
| Absolute bolometric magnitude (Mbol) | 7.96 |
| Orbit | |
| Primary | Gliese 229 A |
| Name | Gliese 229 B |
| Period (P) | 349+37 −29 years |
| Semi-major axis (a) | 42.9+3.0 −2.4 AU |
| Eccentricity (e) | 0.736+0.014 −0.011 |
| Inclination (i) | 47.7+2.5 −2.9° |
| Longitude of the node (Ω) | 168.3+0.3 −0.4° |
| Periastron epoch (T) | 2,466,912+97 −63 |
| Argument of periastron (ω) (secondary) | 358.285+0.836 −0.846° |
| Semi-amplitude (K1) (primary) | 0.081674+0.001688 −0.001680 km/s |
| Orbit | |
| Primary | Gliese 229 Ba |
| Name | Gliese 229 Bb |
| Period (P) | 12.1343+0.0012 −0.0013 days |
| Semi-major axis (a) | 0.0424±0.0004 AU |
| Eccentricity (e) | 0.2306+0.0025 −0.0026 |
| Inclination (i) | 31.4+0.5 −0.6° |
| Longitude of the node (Ω) | 210.4+1.5 −1.4° |
| Periastron epoch (T) | 2,460,378.38±0.04 |
| Argument of periastron (ω) (secondary) | 3.2±1.1° |
| Details | |
| A | |
| Mass | 0.581±0.007 M☉ |
| Radius | 0.549±0.043 R☉ |
| Luminosity (bolometric) | 0.0430 L☉ |
| Surface gravity (log g) | 4.695±0.035 cgs |
| Temperature | 3,700 K |
| Metallicity | −0.02±0.06 |
| Rotation | 28.9±1.6 d |
| Rotational velocity (v sin i) | 1 km/s |
| Ba | |
| Mass | 37.7±1.1 MJup |
| Radius | 0.81+0.05 −0.12 RJup |
| Luminosity (bolometric) | 3.890+0.375 −0.342×10−6 L☉ |
| Surface gravity (log g) | 5.15±0.04 cgs |
| Temperature | 900+78 −29 K |
| Metallicity | 0.00+0.04 −0.03 |
| Age | 2.45±0.20 Gyr |
| Bb | |
| Mass | 33.4±1.0 MJup |
| Radius | 0.85+0.12 −0.05 RJup |
| Luminosity (bolometric) | 2.630+0.254 −0.231×10−6 L☉ |
| Surface gravity (log g) | 5.07+0.04 −0.011 cgs |
| Temperature | 775+20 −33 K |
| Metallicity | 0.00+0.04 −0.03 |
| Age | 2.45±0.20 Gyr |
| Other designations | |
| NSV 2863, BD−21°1377, GJ 229, HD 42581, HIP 29295, SAO 171334, LHS 1827, TYC 5945-765-1 | |
| Database references | |
| SIMBAD | A |
| B | |
| Exoplanet Archive | data |
Gliese 229 (also written as Gl 229 or GJ 229) is a multiple system composed of a red dwarf and two brown dwarfs, located 18.8 light years away in the constellation Lepus. The primary component has 58% of the mass of the Sun, 55% of the Sun's radius, and a very low projected rotation velocity of 1 km/s at the stellar equator.