Astronomy:2MASS J09373487+2931409
Coordinates: 
09h 37m 34.9s, +29° 31′ 41″
| Observation data Equinox J2000.0]] (ICRS) | |
|---|---|
| Constellation | Leo |
| Right ascension | 09h 37m 34.9s |
| Declination | 29° 31′ 41″ |
| Characteristics | |
| Spectral type | T6p |
| Astrometry | |
| Proper motion (μ) | RA: 944.15 ± 1.24 mas/yr Dec.: −1319.78 ± 1.21 mas/yr |
| Parallax (π) | 163.39 ± 1.76[1] mas |
| Distance | 20.0 ± 0.2 ly (6.12 ± 0.07 pc) |
| Details | |
| Mass | 41.56±25.72[2] MJup |
| Radius | 0.94±0.16[2] RJup |
| Luminosity | 0.000005[2] L☉ |
| Surface gravity (log g) | 4.97±0.48[2] cgs |
| Temperature | 881±74[2] K |
| Age | 0.5-10[2] Gyr |
| 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 | |
2MASS J09373487+2931409, or 2MASSI J0937347+293142 (abbreviated to 2MASS 0937+2931) is a brown dwarf of spectral class T6,[3][4] located in the constellation Leo about 19.96 light-years from Earth.[1]
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]
Distance
Currently the most precise distance estimate of 2MASS 0937+2931 is trigonometric parallax, published in 2009 by Schilbach et al.: 163.39 ± 1.76 mas, corresponding to a distance 6.12 ± 0.07 pc, or 19.96 ± 0.22 ly.[1] A less precise parallax of this object, measured under U.S. Naval Observatory Infrared Astrometry Program, was published in 2004 by Vrba et al.[5]
Properties
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 about 800 Kelvin. The Research Consortium On Nearby Stars (RECONS) estimates the brown dwarf to be 0.03 solar masses.[6] No optical variability was detected as in 2014.[7]
See also
The other 10 brown dwarfs, presented in Burgasser et al. (2002):[3]
- 2MASS 0243-2453 (T6)
- 2MASS 0415-0935 (T8)
- 2MASS 0727+1710 (T7)
- List of stars in Leo
References
- ↑ 1.0 1.1 1.2 Schilbach, E.; Röser, S.; Scholz, R.-D. (2009). "Trigonometric parallaxes of ten ultracool subdwarfs". Astronomy and Astrophysics 493 (2): L27–L30. doi:10.1051/0004-6361:200811281. Bibcode: 2009A&A...493L..27S.
- ↑ 2.0 2.1 2.2 2.3 2.4 2.5 Filippazzo, Joseph C.; Rice, Emily L.; Faherty, Jacqueline; Cruz, Kelle L.; Van Gordon, Mollie M.; Looper, Dagny L. (2015), "Fundamental Parameters and Spectral Energy Distributions of Young and Field Age Objects with Masses Spanning the Stellar to Planetary Regime", The Astrophysical Journal 810 (2): 158, doi:10.1088/0004-637X/810/2/158
- ↑ 3.0 3.1 3.2 3.3 Burgasser, Adam J.; Kirkpatrick, J. Davy; Brown, Michael E.; Reid, I. Neill; Burrows, Adam; Liebert, James; Matthews, Keith; Gizis, John E. et al. (2002). "The Spectra of T Dwarfs. I. Near-Infrared Data and Spectral Classification". The Astrophysical Journal 564 (1): 421–451. doi:10.1086/324033. Bibcode: 2002ApJ...564..421B.
- ↑ "2MASS J09373487+2931409 -- Brown Dwarf (M<0.08solMass)". SIMBAD. Centre de Données astronomiques de Strasbourg. http://simbad.u-strasbg.fr/simbad/sim-id?Ident=2MASS+J09373487%2B2931409.
- ↑ Vrba, F. J.; Henden, A. A.; Luginbuhl, C. B.; Guetter, H. H.; Munn, J. A.; Canzian, B.; Burgasser, Adam J.; Kirkpatrick, J. Davy et al. (2004). "Preliminary Parallaxes of 40 L and T Dwarfs from the US Naval Observatory Infrared Astrometry Program". The Astronomical Journal 127 (5): 2948–2968. doi:10.1086/383554. Bibcode: 2004AJ....127.2948V.
- ↑ "The 100 nearest star systems". Georgia State University. January 1, 2012. http://www.astro.gsu.edu/RECONS/TOP100.posted.htm.
- ↑ Heinze, Aren N.; Metchev, Stanimir; Kellogg, Kendra (2014), "Weather on Other Worlds. III. A Survey for T Dwarfs with High-Amplitude Optical Variability", The Astrophysical Journal 801 (2): 104, doi:10.1088/0004-637X/801/2/104
External links
- Burgasser et al.: A Method for Determining the Physical Properties of the Coldest Known Brown Dwarfs"; in: The Astrophysical Journal, Vol. 639, Issue 2, S. 1095ff. (2006)
- Cushing et al.: A Spitzer Infrared Spectrograph Spectral Sequence of M, L, and T Dwarfs"; in: The Astrophysical Journal, Vol. 648, Issue 1, S. 614ff. (2006)
 |  |
