2M0838+15 (also known as 2MASS J08381155+1511155) is a triple brown dwarf with all three components being T dwarfs. It was the first fully resolved triple T-type brown dwarf system that was discovered.[1]
 Keck Observatory image of 2M0838+15ABC | |
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Cancer |
| Right ascension | 08h 38m 11.55s |
| Declination | +15° 11′ 15.51″ |
| Characteristics | |
| Evolutionary stage | brown dwarf |
| Spectral type | T3+T3+T4.5[1] |
| Astrometry | |
| Proper motion (μ) | RA: -139.0 ±1.9 mas/yr[2] Dec.: 5.9 ±1.8 mas/yr[2] |
| Distance | 160 ±39 ly (49 ±12 pc)[1] |
| Details[1] | |
| 2M0838+15A | |
| Mass | 63 ±9 MJup |
| 2M0838+15B | |
| Mass | 58 ±8 MJup |
| 2M0838+15C | |
| Mass | 52 ±8 MJup |
| Position (relative to 2M0838+15A)[1] | |
| Component | 2M0838+15(BC) |
| Epoch of observation | 2010 January 8 |
| Angular distance | 549 ±1 mas |
| Position angle | 18.8 ±0.1° |
| Projected separation | 27 ±5 AU |
| Position (relative to 2M0838+15B)[1] | |
| Component | 2M0838+15C |
| Epoch of observation | 2010 January 8 |
| Angular distance | 50.2 ±0.5 mas |
| Position angle | -6 ± 2° |
| Projected separation | 2.5 ±0.5 AU |
| Other designations | |
| Database references | |
| SIMBAD | data |
Description
edit2M0838+15 was discovered in a cross-match of 2MASS and WISE as a possible T6-T7 dwarf.[3] An unresolved spectrum with NASA IRTF was obtained. Follow-up imaging observations with Keck NIRC2 showed that this system is a triple system. Follow-up observations with Keck/OSIRIS resulted in resolved spectrum of the A and the BC components. The spectrum for component A matches a T3 ±1 spectral type. The BC spectrum matches a combined spectral type, which is composed of T3 ± 1 (B), and T4.5 ± 1 (C). Follow-up imaging showed that the triple has a common proper motion. Components BC have a relative small separation of around 2.5 AU and should have an orbital period of around 12 or 21 years. This could mean that in the future the masses can be measured for both components by using the dynamical mass method. For an age of 3 billion years the researchers estimate masses of 63+58+52 MJ, and for an age of 300 million years the researchers estimate masses of 21+19+17 MJ. The researchers find that for an age of 3 billion years the system would have a gravitational binding energy of about 20 × 1041 erg. This would be high enough for the system to survive a dynamical ejection from a star-forming region. For an age of 300 million years, the gravitational binding energy is about 1.6 × 1041 erg, which would make it a rare weakly bound triple. The researchers conclude that it is less likely that 2M0838+15 is young.[1]
See also
editother triple brown dwarfs:
- DENIS-P J020529.0−115925
- 2M1510 includes eclipsing binary pair
- VHS J1256–1257
- 2MASS J0920+3517
References
edit- ^ a b c d e f g Radigan, Jacqueline; Jayawardhana, Ray; Lafrenière, David; Dupuy, Trent J.; Liu, Michael C.; Scholz, Alexander (2013-11-01). "Discovery of a Visual T-dwarf Triple System and Binarity at the L/T Transition". The Astrophysical Journal. 778 (1): 36. arXiv:1308.5702. Bibcode:2013ApJ...778...36R. doi:10.1088/0004-637X/778/1/36. ISSN 0004-637X.
- ^ Best, William M. J.; Magnier, Eugene A.; Liu, Michael C.; Aller, Kimberly M.; Zhang, Zhoujian; Burgett, W. S.; Chambers, K. C.; Draper, P.; Flewelling, H.; Kaiser, N.; Kudritzki, R. -P.; Metcalfe, N.; Tonry, J. L.; Wainscoat, R. J.; Waters, C. (2018-01-01). "Photometry and Proper Motions of M, L, and T Dwarfs from the Pan-STARRS1 3π Survey". The Astrophysical Journal Supplement Series. 234 (1): 1. arXiv:1701.00490. Bibcode:2018ApJS..234....1B. doi:10.3847/1538-4365/aa9982. ISSN 0067-0049.
- ^ Aberasturi, M.; Solano, E.; Martín, E. L. (2011-10-01). "WISE/2MASS-SDSS brown dwarfs candidates using Virtual Observatory tools". Astronomy and Astrophysics. 534: L7. arXiv:1108.1724. Bibcode:2011A&A...534L...7A. doi:10.1051/0004-6361/201117822. ISSN 0004-6361.