2MASS J05325346+8246465
Observation data
Epoch J2000[1]      Equinox J2000[1]
Constellation Camelopardalis
Right ascension 05h 32m 53.46s[1]
Declination +82° 46 46.5[1]
Characteristics
Spectral type L7[1]
Astrometry
Parallax (π)40.2369 ± 0.6389 mas[1]
Distance81 ± 1 ly
(24.9 ± 0.4 pc)
Details
Mass0.077–0.085[2] M
Temperature1600[3] K
Metallicity [Fe/H]-1.6[3] dex
Age~10[3] Gyr
Other designations
2MASS J05325346+8246465,[1]
2MASS 0532+8246
Database references
SIMBADdata

2MASS J05325346+8246465 (abbreviated 2MASS J0532+8246) is possibly the first brown dwarf observed in the galactic halo of the Milky Way, and the first known substellar subdwarf star.[4][5] It was discovered from Two Micron All-Sky Survey data, and verified by observations at Palomar Observatory and W. M. Keck Observatory.[5] It has a low metallicity, which indicates it is an old star.[5]

The mass and temperature of 2MASS 0532+8246 makes it a rare object in stellar-substellar gap between conventional stars and brown dwarfs.[6] It produces roughly half of its luminosity from hydrogen fusion.[3] Such "gap" objects, covering a narrow range of masses but a wide range of temperatures, and powered by unsteady hydrogen fusion, are exotic but expected to be more common among low-metallicity objects like 2MASS J05325346+8246465.[7]

References

  1. 1 2 3 4 5 6 7 "2MASS J05325346+8246465 -- Brown Dwarf (M<0.08solMass)". SIMBAD. Centre de Données astronomiques de Strasbourg. Retrieved 2018-12-04.
  2. Burgasser, Adam J.; Kirkpatrick, J. Davy; Burrows, Adam; Liebert, James; Reid, I. Neill; Gizis, John E.; McGovern, Mark R.; Prato, L.; McLean, Ian S. (2003). "The First Substellar Subdwarf? Discovery of a Metal‐poor L Dwarf with Halo Kinematics". The Astrophysical Journal. 592 (2): 1186–1192. arXiv:astro-ph/0304174. Bibcode:2003ApJ...592.1186B. doi:10.1086/375813. S2CID 11895472.
  3. 1 2 3 4 Allard, F.; Pinfield, D. J.; Zapatero Osorio, M. R.; Lodieu, N.; Gálvez-Ortiz, M. C.; Burgasser, A. J.; Zhang (张曾华), Z. H. (2019), "Primeval very low-mass stars and brown dwarfs – VI. Population properties of metal-poor degenerate brown dwarfs", Monthly Notices of the Royal Astronomical Society, 486: 1260–1282, arXiv:1903.05536, doi:10.1093/mnras/stz777
  4. 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. S2CID 18160586.
  5. 1 2 3 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): 1186–1192. arXiv:astro-ph/0304174. Bibcode:2003ApJ...592.1186B. doi:10.1086/375813. S2CID 11895472.
  6. Zhang 张曾华, Z. H.; Homeier, D.; Pinfield, D. J.; Lodieu, N.; Jones, H. R. A.; Allard, F.; Pavlenko, Ya. V. (2017), "Primeval very low-mass stars and brown dwarfs – II. The most metal-poor substellar object", Monthly Notices of the Royal Astronomical Society, 468 (1): 261–271, arXiv:1702.02001, Bibcode:2017MNRAS.468..261Z, doi:10.1093/mnras/stx350, S2CID 54847595
  7. Schneider, Adam C.; Burgasser, Adam J.; Gerasimov, Roman; Marocco, Federico; Gagné, Jonathan; Goodman, Sam; Beaulieu, Paul; Pendrill, William; Rothermich, Austin; Sainio, Arttu; Kuchner, Marc J.; Caselden, Dan; Meisner, Aaron M.; Faherty, Jacqueline K.; Mamajek, Eric E.; Hsu, Chih-Chun; Greco, Jennifer J.; Cushing, Michael C.; Kirkpatrick, J. Davy; Bardalez-Gagliuffi, Daniella; Logsdon, Sarah E.; Allers, Katelyn; Debes, John H.; The Backyard Worlds; Planet 9 Collaboration (2020), "WISEA J041451.67–585456.7 and WISEA J181006.18–101000.5: The First Extreme T-type Subdwarfs?", The Astrophysical Journal, 898 (1): 77, arXiv:2007.03836, Bibcode:2020ApJ...898...77S, doi:10.3847/1538-4357/ab9a40, S2CID 220403370{{citation}}: CS1 maint: numeric names: authors list (link)


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