0 Detection of H α Emission in a Methane ( T - type ) Brown Dwarf
نویسندگان
چکیده
We report the detection of Hα emission in the T dwarf (methane brown dwarf) 2MASSW J1237392+652615 over three days using the Keck Low Resolution Imaging Spectrograph. The measured line flux, log(LHα/Lbol) = −4.3, is roughly consistent with early M dwarf activity levels and inconsistent with decreasing activity trends in late M and L dwarfs. Similar emission is not seen in two other T dwarfs. We speculate on several mechanisms that may be responsible for emission, including a strong magnetic field, continuous flaring, acoustic heat generation, and a close (a ∼ 4 20 RJup) interacting binary, with the cooler component overflowing its Roche lobe. We suggest that the M9.5Ve PC 0025+0447 could be a warm analogue to 2MASS J1237+65, and may be powered by the latter mechanism. Subject headings: radiation mechanisms: non-thermal — stars: activity — stars: individual (2MASSW J1237392+652615, SDSSp J162414.37+002915.6, SDSSp J134646.45003150.4) — stars: low mass, brown dwarfs
منابع مشابه
Detection of H Emission in a Methane (t-type) Brown Dwarf
We report the detection of H emission in the T dwarf (methane brown dwarf) 2MASSW J1237392+652615 over three days using the Keck Low Resolution Imaging Spectrograph. The measured line ux, log(L H /L bol) = ?4.3, is roughly consistent with early M dwarf activity levels and inconsistent with decreasing activity trends in late M and L dwarfs. Similar emission is not seen in two other T dwarfs. We ...
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