2MASS J21392676+0220226
Brown dwarf star in the constellation Aquarius
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2MASS J21392676+0220226 (or CFBDS J213926+02202) is a brown dwarf located 34 light-years (10 parsecs) from Earth in the constellation Aquarius.[6] Its surface is thought to be host to a massive storm,[7] resulting in large variability of its color.[8] It is a member of the Carina-Near moving group.[3] This brown dwarf was discovered in the Two Micron All-Sky Survey (2MASS).
| Observation data Epoch J2000 Equinox ICRS | |
|---|---|
| Constellation | Aquarius[1] |
| Right ascension | 21h 39m 26.769s[2] |
| Declination | +02° 20′ 22.70″[2] |
| Characteristics | |
| Spectral type | T1.5[3] |
| Apparent magnitude (J) | 14.710[4] |
| Apparent magnitude (H) | 14.16[2] |
| Apparent magnitude (K) | 13.58[2] |
| Astrometry | |
| Radial velocity (Rv) | −25.1±0.3[3] km/s |
| Proper motion (μ) | RA: 489.7±0.7 mas/yr[3] Dec.: 125.0±0.8 mas/yr[3] |
| Parallax (π) | 96.5±1.1 mas[3] |
| Distance | 33.8 ± 0.4 ly (10.4 ± 0.1 pc) |
| Details | |
| Mass | 14.6+3.2 −1.6[3] MJup |
| Radius | 1.17+0.02 −0.04[3] RJup |
| Surface gravity (log g) | 4.42+0.12 −0.06[3] cgs |
| Temperature | 1111+37 −42[3] K |
| Rotation | 7.614±0.178 h[5] |
| Age | 200±50[3] Myr |
| Other designations | |
| CFBDS J213926+022023, 2MUCD 20912, WISEP J213927.09+022023.7 | |
| Database references | |
| SIMBAD | data |
The clouds on this brown dwarf are modelled as patchy, high-altitude forsterite cloud above a deeper, optically thick iron cloud. The silicate clouds cover 75–91% of the surface of this brown dwarf.[9] An alternative model from around 2016 can explain the variability and atmosphere of this brown dwarf without clouds.[10]
Once thought to be a binary object based on a 2010 study,[11][12] it has since been shown to in fact be single.[13][14]
