2MASS J10475385+2124234 (abbreviated to2MASS J1047+21) is abrown dwarf ofspectral class T6.5, in theconstellationLeo. This object lies at a distance of 34light-years fromEarth. It first attracted attention by becoming the first brown dwarf ofspectral class T from which radio waves were detected. This discovery then permitted its wind speeds to be computed.
2MASS J1047+21 was discovered in 1999 along with eight other brown dwarf candidates during theTwo Micron All-Sky Survey (2MASS), conducted from 1997 to 2001. Follow-up observations with theKeck I 10-meter telescope'sNear Infrared Camera (NIRC) were conducted on 27 May 1999 and identifiedmethane in 2MASS J1047+21's near-infrared spectrum, classifying it as aT-type brown dwarf.[7]
In 2010, astronomers using theArecibo radio telescope discovered bursts of low-frequency radio waves coming from 2MASS J1047+21. This radio emission comes from electrons spiraling around the magnetic field lines of the brown dwarf.[8][9] Since the frequency of the radio emission is linked to the strength of the magnetic field, the team measured a magnetic field strength of 1.7 kG. The bursts were also found to drift in frequency, in a manner reminiscent of certain types ofsolar radio emission. The radio emissions, together with the detection ofHα, which is usually found in stellarchromospheres, shows that 2MASS J1047+21 is magnetically active.
The wind speed is directly inferred from minute, regular cycles in its visible (which matches its ultra-violet) appearance compared to the same at radio wave spectra.[10][11][12][13] The radio emissions are coming from electrons interacting with the magnetic field, which is rooted deep in the interior.[12] The visible and infrared (IR) data, on the other hand, reveal what's happening in the gas giant's cloud tops.[12]
^Faherty, Jacqueline K.; Burgasser, Adam J.; Cruz, Kelle L.; Shara, Michael M.; Walter, Frederick M.; Gelino, Christopher R. (1 January 2009). "THE BROWN DWARF KINEMATICS PROJECT I. PROPER MOTIONS AND TANGENTIAL VELOCITIES FOR A LARGE SAMPLE OF LATE-TYPE M, L, AND T DWARFS".The Astronomical Journal.137 (1):1–18.arXiv:0809.3008.doi:10.1088/0004-6256/137/1/1.
^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-Escudé, Guillem (10 June 2012). "THE BROWN DWARF KINEMATICS PROJECT (BDKP). III. PARALLAXES FOR 70 ULTRACOOL DWARFS".The Astrophysical Journal.752 (1): 56.arXiv:1203.5543.doi:10.1088/0004-637X/752/1/56.
^abcFilippazzo, Joseph C.; Rice, Emily L.; Faherty, Jacqueline; Cruz, Kelle L.; Van Gordon, Mollie M.; Looper, Dagny L. (September 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): 46.arXiv:1508.01767.Bibcode:2015ApJ...810..158F.doi:10.1088/0004-637X/810/2/158.S2CID89611607. 158.
^Burgasser, Adam J.; Kirkpatrick, J. Davy; Brown, Michael E.; Reid, I. Neill; Gizis, John E.; Dahn, Conard C.; et al. (September 1999). "Discovery of Four Field Methane (T-Type) Dwarfs with the Two Micron All-Sky Survey".The Astrophysical Journal.522 (1):L65 –L68.arXiv:astro-ph/9907019.Bibcode:1999ApJ...522L..65B.doi:10.1086/312221.S2CID15326092.
_on_Jul_14_2020_aligned_to_stars.jpg)
