ATMOSPHERIC, EVOLUTIONARY, AND SPECTRAL MODELS OF THE BROWN DWARF GLIESE-229-B

Theoretical spectra and evolutionary models that span the giant planet -brown dwarf continuum have been computed based on the recent discover y of the brown dwarf Gliese 229 B. A flux enhancement in the 4- to 5-m icrometer wavelength window is a universal feature from jovian planets to brown dwarfs, Model results confirm the existence of methane and w ater in the spectrum of Gliese 229 B and indicate that its mass is 30 to 55 jovian masses, Although these calculations focus on Gliese 229 B , they are also meant to guide future searches for extrasolar giant pl anets and brown dwarfs.