123.03 - The Universal Presence of Nightside Clouds in Spitzer Phase Curve Observations of Hot Jupiters

Date & Time

Jan 7th at 2:30 PM until 2:40 PM




Rating ( votes)

Author(s): T. Beatty, A.P. Showman, University of Arizona, Tucson, Arizona, UNITED STATES|M. Marley, NASA Ames, Moffet Field, California, UNITED STATES|B.S. Gaudi, Ohio State University, Columbus, Ohio, UNITED STATES|K. Colon, NASA Goddard, Greenbelt, Maryland, UNITED STATES|J. Fortney, UC Santa Cruz, Santa Cruz, California, UNITED STATES|
Institution(s): 1. University of Arizona, Tucson, AZ, United States. 2. NASA Ames, Moffet Field, CA, United States. 3. Ohio State University, Columbus, OH, United States. 4. NASA Goddard, Greenbelt, MD, United States. 5. UC Santa Cruz, Santa Cruz, CA, United States.
Contributing team(s): (none)
We recently observed two full orbital phase curves of the 27 MJ transiting brown dwarf KELT-1b using the Spitzer Space Telescope. Both the day-night temperature contrasts and the hotspot offsets we measure for KELT-1b are in line with the trends seen by Spitzer in lower mass hot Jupiters, despite the fact that KELT-1b should have an atmospheric advective timescale substantially longer than in a typical hot Jupiter at Spitzer wavelengths. We therefore suggest that nightside clouds are playing a noticeable role in modulating the thermal emission from all hot Jupiters, based on these observations and: 1) the lack of a clear trend in phase offsets with equilibrium temperature, 2) the sharp day-night transitions needed to have non-negative intensity maps, 3) the fact that all the nightsides of these objects appear to be at roughly the same temperature of 1050K, while the dayside temperatures increase linearly with equilibrium temperature, and 4) the trajectories of these objects on a Spitzer color-magnitude-diagram, which show colors explainable via nightside clouds.