16296

To date three brown dwarfs in the L-T transition show signs of planetary-wave light-curve beating. Here comma the differential rotation of wave-derived structure in various latitudinal bands causes their individual light curves alternately to constructively and destructively interfere. Luhman 16AB is an intriguing target comma with both components exhibiting peculiar behaviors that hint to the existence of bands in their atmospheres. Recently comma indirect evidence for bands on Luhman 16A were found using polarization. However comma no data exists to date that is able to verify the existence of bands on 16A or B. We propose to observe Luhman 16AB with WFC3 to test the existence of bands in these two L-T transition brown dwarfs. Our observations will 1) test the hypothesis that there are planetary-scale waves and bands in L-T transition atmospheres comma 2) verify the ability of polarization to detect bands in exoatmospheres comma and 3) nearly double the sample of long-temporal-baseline observations available to detect planetary-scale waves in L-T transition brown dwarfs.