Near Infrared Spectra of L/T Transition Brown Dwarfs

We present medium resolution (R ~ 3500) NIR spectra of several L/T transition brown dwarfs obtained with TripleSpec on the Astrophysical Research Consortium 3.5 meter telescope at Apache Point Observatory. Some of these brown dwarfs have no previously published NIR spectra. L/T transition objects commonly undergo a “J-band brightening”, which is a reversal in the evolutionary trend where the object emits more flux in the J band than in the K band. We believe that the J-band brightening can be attributed to holes forming in the upper atmosphere, which allows more short wavelength flux to pass through the cloud layer. We selected our targets based on their J–K colors in the L/T transition and we compare their spectra to that of other transition objects. We also plan to run spectral binary fitting code on the data to determine whether these objects are binaries or good matches to cloud-clearing models.