2MASS J11145133−2618235
Brown dwarf star in the constellation Hydra
From Wikipedia, the free encyclopedia
2MASS J11145133−2618235 (designation abbreviated to 2MASS 1114−2618), [3] or 2M1114−26,[2] or 2M1114−2618,[2] or 2MASS 1114−26,[4] or 2MASS J1114−2618[6]) is a nearby brown dwarf of spectral class T7.5, located in constellation Hydra[a] at approximately 18 light-years from Earth.[10]
| Observation data Epoch J2000[1] Equinox J2000[1] | |
|---|---|
| Constellation | Hydra |
| Right ascension | 11h 14m 51.337s[1] |
| Declination | −26° 18′ 23.56″[1] |
| Characteristics | |
| Spectral type | T7.5[2][3][4][5][6] |
| Apparent magnitude (i (GMOS filter system)) | 23.21 ± 0.09[5] |
| Apparent magnitude (z (GMOS filter system)) | 19.59 ± 0.04[5] |
| Apparent magnitude (J (2MASS filter system)) | >15.86 ± 0.08[2][3] |
| Apparent magnitude (J (MKO filter system)) | 15.52 ± 0.05[6] |
| Apparent magnitude (H (2MASS filter system)) | >15.73 ± 0.12[3] |
| Apparent magnitude (H (MKO filter system)) | 15.82 ± 0.05[6] |
| Apparent magnitude (KS (2MASS filter system)) | >16.1[3] |
| Apparent magnitude (KS (MKO filter system)) | 16.54 ± 0.05[6] |
| Astrometry | |
| Proper motion (μ) | RA: −3023.73 mas/yr[7] Dec.: −380.18 mas/yr[7] |
| Parallax (π) | 185.61±1.81 mas[7] |
| Distance | 17.6 ± 0.2 ly (5.39 ± 0.05 pc) |
| Details | |
| Mass | 0.029–0.048[4] M☉ |
| Mass | 30–50[4] MJup |
| Radius | 1.01±0.11[8] RJup |
| Surface gravity (log g) | 4.97+0.22 −0.40[8] cgs |
| Temperature | 617+5 −3[8] K |
| Metallicity | −0.24+0.12 −0.17[8] |
| Age | 3–8[4] Gyr |
| Other designations | |
| 2MASS J11145133-2618235,[1][2] 2MASS 1114-2618,[3] 2M1114−26,[2] 2M1114−2618,[2] 2MASS 1114−26,[4] 2MASS J1114−2618,[6] WISE J111448.79−261827.7[9] | |
| Database references | |
| SIMBAD | data |
  2M1114−26 Location of 2M1114−26 in the constellation Hydra | |
Discovery
2MASS 1114−2618 was discovered in 2005 by C. G. Tinney et al. from the 2MASS Wide-Field T Dwarf Search (WFTS), based on observations obtained at the Anglo-Australian Telescope, Siding Spring, Australia. In 2005 Tinney et al. published a paper in The Astronomical Journal, where they presented discovery of five new brown dwarfs of spectral type T, among which also was 2MASS 1114−2618.[2]
Distance and proper motion
Trigonometric parallax of 2MASS 1114−2618, measured in 2026 by Vrba et al., is 0.1856 ± 0.0018 arcsec, corresponding to a distance 5.39 ± 0.05 pc, or 17.6 ± 0.2 ly.[7]
The photometric distance estimate of 2MASS 1114−2618, published in its discovery paper in 2005, is 7 pc (22.8 ly).[2] Spectrophotometric distance estimate by Kirkpatrick et al. (2012), is 6.6 pc (21.5 ly).[9]
2MASS 1114−2618 has quite a large proper motion of 3047.54 mas/yr with position angle 262.83 degrees, indicating motion in south-west direction on the sky. At distance 17.6 ly (assuming parallax 185.6 ± 1.8 mas), the corresponding tangential velocity is 77.83 km/s.[7]
See also
The other four discoveries of brown dwarfs, presented in Tinney et al. (2005):[2]
- 2MASS 0939−2448 (T8, binary brown dwarf)
Notes
- The nearest known star/brown dwarf in this constellation.