Spitzer Space Telescope - General Observer Proposal #80071


Search for Planetary Mass Companions of Nearby Young Stars

Principal Investigator: Massimo Marengo
           Institution: Iowa State University

     Technical Contact: Massimo Marengo, Iowa State University

Co-Investigators: 
Karl Stapelfeldt, JPL/Caltech                                         
Michael Werner, JPL/Caltech                                           
Joseph Hora, Smithsonian Astrophysical Observatory                    
Giovanni Fazio, Smithsonian Astrophysical Observatory                 
Volker Tolls, Smithsonian Astrophysical Observatory                   
Joseph Carson, College of Charleston                                  
Alan Hulsebus, Iowa State University                                  

Science Category: extrasolar planets 
 Observing Modes: IRAC Post-Cryo Mapping
  Hours Approved: 58.1 

Abstract:
Our view of extrasolar planetary systems was revolutionized in late 2008, when
the first images of planets orbiting 50-100 AU from HR 8799 and Fomalhaut were
announced. These results revealed the existence of giant extrasolar planets
orbiting their host stars at distances comparable to the size of protoplanetary
disks (100-500 AU). Despite their importance to understand the dynamics of the
Kuiper belts of extrasolar systems, their possible role in the creation of
transient debris disks, and the effects that these bodies can have on the
stability of inner planets, little is known about the characteristics of planets
at distances of 100 AU or more. To fill this gap, we propose to search for
planetary mass companions around 23 young nearby stars. Thanks to the young age
(<1 Gyr) and limited distance (<15 pc) of our targets, we will be sensitive to
planets with masses as low as 5 MJ at 150 AU from the host star, and <1 MJ at
300 AU or more orbital separation. These observations will increase by 2-3
magnitudes the sensitivity of previous IRAC searches for low mass companions,
and probe smaller separations from the primary star. This project will provide a
census of planetary mass objects, or strong limits on their existence, in a
currently unexplored region of extrasolar planetary systems. The proposed
observations represent one of the best remaining opportunities to directly image
extrasolar planets in the Spitzer mission.