Spitzer Space Telescope - General Observer Proposal #30825


HD 189733b:  As The World Turns

Principal Investigator: David Charbonneau
           Institution: Harvard

Co-Investigators: 
Jonathan Fortney, NASA Ames Research Center                           
Adam Showman, University of Arizona                                   
Curtis Cooper, University of Arizona                                  
Lori Allen, Smithsonian Astrophysical Observatory                     
Thomas Megeath, Smithsonian Astrophysical Observatory                 
Heather Knutson, Harvard University                                   
Eric Agol, University of Washington                                   
Nicholas Cowan, University of Washington                              

Science Category: extrasolar planets 
 Observing Modes: IracMap 
  Hours Approved: 33.0 

Abstract:
We propose to monitor the closest and brightest transiting exoplanet
system for a time of 33 hours, from just before the start of transit,
to just after the end of secondary eclipse.  Our primary science goal
is the measurement of the planetary phase function, which is the
modulation induced by the changing face of the planet as it orbits the
parent star.  Our secondary science goals are the ultra precise
monitoring of the transit shape and the secondary eclipse curve.  Our
requisite photometric precision has already been demonstarted with
recent observations, and we outline modest changes that will further
increase the performance.  Our proposed observations present an
exciting opportunity to shed light, for the first time, on hot Jupiter
weather patterns, and will extend the realm of planetary meteorology
to other Solar systems.  Specifically, our observations have the
potential to determine (i) the day-night temperature difference, (ii)
the temperature pattern, in particular whether the temperatures are
swept eastward as predicted by recent theoretical modeling, and (iii)
the directions of the km/s winds themselves.  Observation of the
longitudinal temperature structure will also inform debates about
cloud patterns, disequilibrium chemistry, and the influence (if any)
of atmospheric dynamics on long-term planetary evolution.