Spitzer Space Telescope - General Observer Proposal #20101


Day and Night on Hot Jupiters

Principal Investigator: Bradley Hansen
           Institution: UCLA

Co-Investigators: 
Sara Seager, Carnegie Institute of Washington                         
Drake Deming, Goddard Space Flight Center                             
Jeremy Richardson, Goddard Space Flight Center                        
Joe Harrington, Cornell                                               
Kristen Menou, Columbia University                                    
James Cho, Carnegie Institute of Washington                           

Science Category: brown dwarfs/very low mass stars 
 Observing Modes: MipsPhot 
  Hours Approved: 7.6 

Abstract:
Recent observations of the secondary eclipse of the `Hot Jupiter'
planet HD209458b suggest that the planet may reradiate most and
perhaps all of the irradiation it receives from its host star on the
side facing the star i.e.  that there is little redistribution of
energy around the surface of the planet.  An immediate implication of
this day/night temperature difference is that even non-transitting
`Hot Jupiter' planetary systems should show a small flux variation as
the planet orbits the star, showing first its hot day side and then
its cold night side.  We propose to monitor the 24 micron flux
variation of the five brightest stars that host Hot Jupiter planets,
in order to detect the orbital modulation of the total star+planet
flux.  The detection of such variations will provide information on
the nature and atmospheric dynamics of these planets and may even
constrain the inclination of the orbital plane.