Extrasolar Storms : Exploring Cloud Cover and Atmospheric Dynamics in Brown Dwarfs and Exoplanets

Séminaire IPAG de Daniel Apai (Univ. of Arizona), jeudi 11 juillet 2013 à 11h00, IPAG seminar room

Astronomy has entered an exciting new era when the atmospheres of exoplanets can be studied in detail. Observations of directly imaged exoplanets and brown dwarfs revealed the presence of condensate clouds that strongly influence the energy transport through the planetary atmospheres and, therefore, influence the evolution of the atmospheres and the emerging spectra.The physical nature and properties of these cloud layers remain mostly unknown, but pose one of the outstanding challenges in understanding ultracool atmospheres.

I will introduce a new observing technique in this field, rotational phase mapping, that provides an exciting look into the atmospheres and clouds of exoplanets and ultracool brown dwarfs. I will discuss multiple Hubble and Spitzer programs, including a 1,144-hour Exploration Science program, that applies this new technique to a large number of targets. The data paints an exciting and often surprising picture on ultracool photospheres. I will show that the success of this observational technique also motivates future applications to directly imaged giant exoplanets and super-earths, whose photospheres and surface can be mapped in the near future.