Time: 16:00 h
Author: Michael Cushing
The study of brown dwarfs with effective temperatures less than 500 K can offer important insights into the complex physics of ultracool atmospheres, the shape of the initial mass function, and the low-mass limit of star formation. We have been using the Wide-field Infrared Survey Explorer (WISE) to search for just such a population of brown dwarfs and have identified roughly twenty cool browns dwarfs that populate a new spectral class, dubbed 'Y'. In this talk, I will present the discovery of the Y dwarfs, summarize our current understanding of their physical properties, discuss the enigmatic spectral energy distribution of the archetype Y dwarf WISE 1828+2650, and present new HST photometry of the coolest (Teff ~ 250 K) brown dwarf known WISE 0855-0714.