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Detection of H Alpha Emission in a Methane (T-Type) Brown Dwarf

Adam J. Burgasser·J. Davy Kirkpatrick·I. Neill Reid·James Liebert·John E. Gizis·Michael E. Brown
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Abstract

We report the detection of H{$α$} 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(L$_{Hα}$/L$_{bol}$) = $-$4.3, is roughly consistent with early M dwarf activity levels and inconsistent with decreasing activity trends in late M and L dwarfs. Similar emission is not seen in two other T dwarfs. We speculate on several mechanisms that may be responsible for emission, including a strong magnetic field, continuous flaring, acoustic heat generation, and a close ($a$ $\sim$ 4 - 20 R$_{Jup}$) 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.

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Adam J. Burgasser, J. Davy Kirkpatrick, I. Neill Reid, James Liebert, John E. Gizis, Michael E. Brown. 2000-03-20. Detection of H Alpha Emission in a Methane (T-Type) Brown Dwarf. https://doi.org/10.1086/301423

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