Program: GN-2016B-Q-23

The coldest exoplanets and brown dwarfs emit most of their light through an atmospheric window at ~4-5 microns, just like Jupiter. But with JWST set to launch in 2 years, there are no published 5 micron spectra of extrasolar planets or brown dwarfs colder than 700 K. Recently, our team obtained the first spectrum of WISE 0855, a 250 K brown dwarf, using Gemini/GNIRS at 5 microns. The spectrum reveals water vapor, clouds, and an overall appearance that is strikingly similar to Jupiter. We are now proposing to extend the use of 5 micron spectroscopy to a sequence of brown dwarfs spanning 700 K to 250 K, with the goal of understanding how water vapor, clouds, and non-equilibrium chemistry vary with temperature. Obtaining these observations now will allow us to refine our exoplanet and brown dwarf atmosphere models at thermal infrared wavelengths in time for JWST.