2MASS J09373487+2931409
T-type brown dwarf in the constellation Leo
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2MASS J09373487+2931409, or 2MASSI J0937347+293142 (abbreviated to 2MASS 0937+2931) is a brown dwarf of spectral class T6,[3][6] located in the constellation Leo about 19.96 light-years from Earth.[7]
| Observation data Epoch J2000 Equinox ICRS | |
|---|---|
| Constellation | Leo[1] |
| Right ascension | 09h 37m 34.8797s[2] |
| Declination | +29° 31′ 40.991″[2] |
| Characteristics | |
| Spectral type | T6p[3] |
| Apparent magnitude (J) | 14.648±0.036[2] |
| Apparent magnitude (H) | 14.703±0.068[2] |
| Apparent magnitude (K) | 15.267±0.130[2] |
| Astrometry | |
| Proper motion (μ) | RA: +941.6 mas/yr[4] Dec.: −1324 mas/yr[4] |
| Parallax (π) | 167.19±1.22 mas[4] |
| Distance | 19.5 ± 0.1 ly (5.98 ± 0.04 pc) |
| Details | |
| Mass | 42±26[5] MJup |
| Radius | 0.94±0.16[5] RJup |
| Luminosity | 0.000005[5] L☉ |
| Surface gravity (log g) | 4.97±0.48[5] cgs |
| Temperature | 881±74[5] K |
| Other designations | |
| 2MASS J09373487+2931409 2MASSI J0937347+293142 2MASS 0937+2931 | |
| Database references | |
| SIMBAD | data |
  2MASS 0937+2931 Location of 2MASS 0937+2931 in the constellation Leo | |
Discovery
2MASS 0937+2931 was discovered in 2002 by Adam J. Burgasser et al. from Two Micron All-Sky Survey (2MASS), conducted from 1997 to 2001. Follow-up observations were made in 1998–2001 using the Near-Infrared Camera, mounted on the Palomar 60 inch (1.5 m) Telescope; CTIO Infrared Imager (CIRIM) and Ohio State Infrared Imager/Spectrometer (OSIRIS), mounted on the Cerro Tololo Inter-American Observatory (CTIO) 1.5 m Telescope; and some additional observations were made using the Near Infrared Camera (NIRC), mounted on the Keck I 10 m telescope, and nearinfrared camera D78, mounted on the Palomar 5 m Hale Telescope. In 2002 Burgasser et al. published a paper, where they defined new spectral subtypes T1—T8, and presented discovery of 11 new T-type brown dwarfs, among which also was 2MASS 0937+2931. This 11 objects were among the earliest T-type brown dwarfs ever discovered: before this, the total number of known T-type objects was 13, and this discoveries increased it up to 24 (apart from additional T-type dwarfs, identified by Geballe et al. 2001 in SDSS data).[3]
Properties
Currently the most precise distance estimate of 2MASS 0937+2931 is a trigonometric parallax, published in 2026 by Vrba et al.: 167.19±1.22 mas, corresponding to a distance of 19.50 ± 0.13 light-years (5.98 ± 0.04 parsecs).[4]
2MASS 0937+2931 has an unusual spectrum, indicating a metal-poor atmosphere and/or a high surface gravity (high pressure at the surface).[3] Its effective temperature is estimated at 800 Kelvin. The Research Consortium On Nearby Stars (RECONS) estimates the brown dwarf to be 0.03 solar masses.[8] No optical variability was detected as in 2014.[9]
See also
Other brown dwarfs presented in Burgasser et al. (2002):[3]
- 2MASS 0243-2453 (T6)
- 2MASS 0415-0935 (T8)
- 2MASS 0727+1710 (T7)