Identifying cloud-clearing brown dwarfs in the L/T transition using binary fitting codes

The identification of possible cloud-clearing brown dwarfs can be determined using spectral binary fitting codes and by analyzing their light curves. Brown dwarfs that are called cloud-clearing have holes in their cloud layers that are also similar to some extrasolar planets. The holes appear when a brown dwarf cools to a temperature that causes its clouds to sink below its photosphere. The spectral type of these objects are within the transition from the L and T class (L/T transition) of brown dwarfs, which is identified by the presence of methane absorption features in the near-infrared. We began our study by selecting brown dwarf targets from the L/T transition and obtained their spectra from spectral archives. Since the spectra of cloud-clearing brown dwarfs are due to both the flux from the warmer holes and the cooler clouds, their spectra resemble brown dwarf binaries. So we ran our target spectra through our binary codes to test for binarity. We then did a literature search to see which of our targets have published light curves. The targets that show sinusoidal variability in their light curves are indicative of cloud-clearing brown dwarfs. We have identified two cloud-clearing brown dwarfs using the above methods: SIMP 0136+09 and SD 0758+32. We will discuss information about their surface properties determined by the binary codes, and relate those properties to exoplanetary atmospheres.