2MASS 0532+8246

2MASS 0532+8246 (full designation 2MASS J05325346+8246465) is possibly the first brown dwarf observed in the galactic halo of the Milky Way, and the first known substellar subdwarf star.[3][2] It was discovered from Two Micron All-Sky Survey data, and verified by observations at Palomar Observatory and W. M. Keck Observatory.[2] It has a low metallicity, which indicates it is an old star.[2] With an age of 12.5 billion years, it is the oldest known brown dwarf star.

2MASS J05325346+8246465

Observation data Epoch J2000[1]      Equinox J2000[1]
Constellation	Camelopardalis
Right ascension	05^h 32^m 53.46^s[1]
Declination	+82° 46′ 46.5″[1]
Characteristics
Spectral type	L7[1]
Astrometry
Parallax (π)	40.24 ± 0.64[1] mas
Distance	81 ± 1 ly (24.9 ± 0.4 pc)
Details
Mass	0.077–0.085 M☉
Metallicity	0.1–0.01[2]
Age	10–15 Gyr
Other designations
2MASS J05325346+8246465,[1] 2MASS 0532+8246
Database references
SIMBAD	data

References

1. "2MASS J05325346+8246465 -- Brown Dwarf (M<0.08solMass)". SIMBAD. Centre de Données astronomiques de Strasbourg. Retrieved 2018-12-04.
2. Burgasser, Adam J. et al. (2003) The First Substellar Subdwarf? Discovery of a Metal-Poor L Dwarf with Halo Kinematics. The Astrophysical Journal, 592(2) 1186.
3. Faherty, Jacqueline K.; Burgasser, Adam J.; Walter, Frederick M.; Van der Bliek, Nicole; Shara, Michael M.; Cruz, Kelle L.; West, Andrew A.; Vrba, Frederick J.; Anglada-Escud, Guillem (2012). "The Brown Dwarf Kinematics Project (BDKP). III. Parallaxes for 70 Ultracool Dwarfs". The Astrophysical Journal. 752 (1): 56. arXiv:1203.5543. Bibcode:2012ApJ...752...56F. doi:10.1088/0004-637X/752/1/56.

External links

• Entry at DwarfArchives.org