  It is now well established that many young brown dwarfs exhibit
characteristics similar to classical T Tauri stars, including infrared excess
from disks and emission lines related to accretion. Whether the same holds true
for even lower mass objects, namely those near and below the Deuterium-burning
limit, is an important question. Here we present optical spectra of six
isolated planetary mass candidates in Chamaeleon II, Lupus I and Ophiuchus
star-forming regions, recently identified by Allers and collaborators to harbor
substantial mid-infrared excesses. Our spectra, from ESO's Very Large Telescope
and New Technology Telescope, show that four of the targets have spectral types
in the ~M9-L1 range, and three of those also exhibit H_alpha. Their
luminosities are consistent with masses of ~5-15 M_{Jupiter} according to
models of Chabrier, Baraffe and co-workers, thus placing these four objects
among the lowest mass brown dwarfs known to be surrounded by circum-sub-stellar
disks. Our findings bolster the idea that free-floating planetary mass objects
could have infancies remarkably similar to those of Sun-like stars and suggest
the intriguing possibility of planet formation around primaries whose masses
are comparable to those of extra-solar giant planets. Another target appears to
be a brown dwarf (~M8) with prominent H_alpha emission, possibly arising from
accretion. The sixth candidate is likely a background source, underlining the
need for spectroscopic confirmation.
