Observation data Epoch J2000 Equinox J2000 | |
---|---|
Constellation | Lepus |
Right ascension | 06h 10m 34.61494s[1] |
Declination | −21° 51′ 52.6564″[1] |
Apparent magnitude (V) | 8.14 |
Characteristics | |
Evolutionary stage | Main sequence / Brown dwarf |
Spectral type | M1Ve [2]+T7+T8[3] |
U−B color index | +1.222[2] |
B−V color index | +1.478[2] |
Variable type | Flare star |
Astrometry | |
Radial velocity (Rv) | 4.23±0.12[1] km/s |
Proper motion (μ) | RA: −135.692(11) mas/yr[1] Dec.: −719.178(17) mas/yr[1] |
Parallax (π) | 173.5740 ± 0.0170 mas[1] |
Distance | 18.791 ± 0.002 ly (5.7612 ± 0.0006 pc) |
Absolute magnitude (MV) | 9.326[4] |
Absolute bolometric magnitude (Mbol) | 7.96[5] |
Orbit[4][6] | |
Primary | Gliese 229 A |
Companion | Gliese 229 B |
Period (P) | 216.925+10.604 −10.352 yr |
Semi-major axis (a) | 28.933+1.008 −1.000 AU |
Eccentricity (e) | 0.853±0.002 |
Inclination (i) | 5.497+0.153 −0.162° |
Longitude of the node (Ω) | 145.946+0.306 −0.294° |
Periastron epoch (T) | 2466912+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[3] | |
Primary | Gliese 229 Ba |
Companion | Gliese 229 Bb |
Period (P) | 12.134±0.003 d |
Semi-major axis (a) | 0.0424±0.0004 AU |
Eccentricity (e) | 0.234±0.004 |
Inclination (i) | 31.4±0.3° |
Longitude of the node (Ω) | 213±2° |
Periastron epoch (T) | 2460378.38±0.04 |
Argument of periastron (ω) (secondary) | 0.7±1.2° |
Details | |
A | |
Mass | 0.579[4] M☉ |
Radius | 0.69[7] R☉ |
Luminosity (bolometric) | 0.0430[4] L☉ |
Luminosity (visual, LV) | 0.0158[nb 1] L☉ |
Temperature | 3,700[5] K |
Rotation | 27.3±0.2 d[8] |
Rotational velocity (v sin i) | 1[9] km/s |
Ba | |
Mass | 38.1±1.0[3] MJup |
Radius | 0.089 ± 0.006[3][a] R☉ |
Radius | 0.884 RJup |
Radius | 61,800 ± 4,050 km |
Luminosity (bolometric) | 3.890+0.375 −0.342×10−6 L☉ |
Surface gravity (log g) | 5.11±0.01[3] cgs |
Temperature | 860±20[3] K |
Age | 2.45±0.20[3] Gyr |
Bb | |
Mass | 34.4±1.5[3] MJup |
Radius | 0.091 ± 0.006[3][a] R☉ |
Radius | 0.907 RJup |
Radius | 63,400 ± 4,400 km |
Luminosity (bolometric) | 2.630+0.254 −0.231×10−6[3] L☉ |
Surface gravity (log g) | 5.03±0.01[3] cgs |
Temperature | 770±20[3] K |
Age | 2.45±0.20[3] Gyr |
Other designations | |
Database references | |
SIMBAD | A |
B | |
Location of Gliese 229 in the constellation Lepus |
Gliese 229 (also written as Gl 229 or GJ 229) is a multiple system composed of a red dwarf and two brown dwarfs[3][10], located 18.8 light years away in the constellation Lepus. The primary component has 58% of the mass of the Sun,[4] 69% of the Sun's radius,[7] and a very low projected rotation velocity of 1 km/s at the stellar equator.[9]
The star is known to be a low activity flare star, which means it undergoes random increases in luminosity because of magnetic activity at the surface. The spectrum shows emission lines of calcium in the H and K bands. The emission of X-rays has been detected from the corona of this star.[11] These may be caused by magnetic loops interacting with the gas of the star's outer atmosphere. No large-scale star spot activity has been detected.[2]
The space velocity components of this star are U = +12, V = –11 and W = –12 km/s.[12] The orbit of this star through the Milky Way galaxy has an eccentricity of 0.07 and an orbital inclination of 0.005.[2]
GaiaDR3
was invoked but never defined (see the help page).mnras214
was invoked but never defined (see the help page).Xuan2024
was invoked but never defined (see the help page).Brandt2021
was invoked but never defined (see the help page).Morales+2008
was invoked but never defined (see the help page).Feng2022
was invoked but never defined (see the help page).apjss71
was invoked but never defined (see the help page).DíezAlonso2019
was invoked but never defined (see the help page).aaa467
was invoked but never defined (see the help page).Whitebook2024
was invoked but never defined (see the help page).Schmitt
was invoked but never defined (see the help page).Gliese1969
was invoked but never defined (see the help page).
Cite error: There are <ref group=nb>
tags on this page, but the references will not show without a {{reflist|group=nb}}
template (see the help page).
Cite error: There are <ref group=lower-alpha>
tags or {{efn}}
templates on this page, but the references will not show without a {{reflist|group=lower-alpha}}
template or {{notelist}}
template (see the help page).