  We analyze an HST/STIS ultraviolet spectrum of the young brown dwarf 2MASSW
J1207334-393254, a member of the ten million-year old TW Hya Association that
has a planetary-mass companion. We detect and identify numerous emission lines.
CIV and other ions are seen that arise in hot gas. We identify a series of
lines with Lyman-pumped H_2 molecular lines, indicating that cool gas is also
present. Overall, this substellar object shows many of the same characteristics
as classical T Tauri stars. We interpret our results as direct evidence of
accretion from a circumstellar gas disk, consistent with previous claims. The
lack of SiIV emission from the accreting gas indicates that silicon has been
depleted into grains.

Astrophysics