Program: GN-2017A-Q-5

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 is only one 5 micron spectrum of an extrasolar planets or brown dwarf colder than 700 K. 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. This proposal is the 2nd of 2 proposals required to complete this project.