Name/Affiliation: J. Sebastian Pineda (Caltech)
A Survey of Auroral Emission from Ultracool Dwarfs
The discovery of pulsed radio emission from brown dwarfs has expanded our understanding of the magnetic phenomenon associated with ultracool objects spanning spectral types M9 to T6. The proposed emission mechanisms necessitate the presence of energetic electron populations cascading down into the upper atmosphere. In Jupiter this magnetospheric interaction leads to auroral emission lines in the ultraviolet, optical and infrared. Recent studies have suggested that similar mechanisms operate in the magnetospheres of cool brown dwarfs. We present preliminary results from our ongoing survey with the Keck telescopes examining the prevalence of optical and infrared aurorae in ultracool dwarfs looking for H-alpha emission in a volume limited sample of T dwarfs and looking for H3+ emission from known radio brown dwarfs.