Irradiated brown dwarfs: Providing insights into exoplanet atmospheres

When:  Thursday, 28^th March 2019

Where:  Robert Hooke Seminar Room

Speaker: Dr Sarah Casewell, University of Leicester 

Hosted by:  Beatriz Mingo

Abstract:

Brown dwarfs are often described as failed stars, however the flip side of this description is that they can also be described as over-ambitious planets. With masses between 13-70 Jupiter masses they have cool atmospheres dominated by cloud features, molecules and show features due to weather.  These atmospheres have a lot of similarities with atmospheres we see in planets in our solar system, and also directly imaged exoplanets.  The question then is: How like hot Jupiters are irradiated brown dwarfs? 

In this seminar I will describe the known irradiated brown dwarfs and how they evolve into post-common envelope systems containing a white dwarf. These rare binaries have very short periods (~hrs) and the brown dwarf is irradiated by the white dwarf companion, often with large amounts of UV radiation. I will discuss the atmospheres of these highly irradiated brown dwarfs and their similarities with irradiated exoplanets.