The transition between the two lowest-luminosity spectral classes of brown dwarfs--the L dwarfs and T dwarfs--is traversed by nearly all brown dwarfs as they cool over time. Yet distinct features of this transition, such as the "J-band bump" and an unusually high rate of multiplicity, remain outstanding problems, although evidence points to condensate cloud evolution as a critical component. Using a Monte Carlo population simulation that incorporates the empirical spectral properties of unresolved brown dwarfs in magnitude-limited samples, I demonstrate that the J-band bump and enhanced multiplicity naturally emerge from a short timescale of photospheric cloud dissipation. This timescale may help constrain future evolutionary models exploring the cloud dissipation process.
@article{arxiv.0810.0570,
title = {Clouds, Brightening and Multiplicity Across the L Dwarf/T Dwarf Transition},
author = {Adam J. Burgasser},
journal= {arXiv preprint arXiv:0810.0570},
year = {2009}
}