Photometric variability of three brown dwarfs

Abstract

We report a study of the photometric variability of 3 low-mass, sub-stellar objects. Two of them, 2MASS 1207334-393254 and 2MASS 1139511-315921, are young (10 Myr) brown dwarfs of M8 spectral class. 2MASS 1207334-393254 was observed in the I, R, J and Y bands, through April--May 2004, and in B and I bands through March--April 2005. 2MASS 1139511-315921 was observed in the I band, from October to December, 2004. The third object, 2MASS 04234858-0414035, a field T dwarf, was observed in the I band.