Spitzer Space Telescope - General Observer Proposal #60161


Cool, spatially resolved substellar and exoplanetary analogues at white dwarfs 

Principal Investigator: Matt  Burleigh
           Institution: University of Leicester

     Technical Contact: Jay Farihi, UCLA

Co-Investigators: 
Jay Farihi, University of Leicester                                   
Ted von Hippel, Siena College                                         
Paul Steele, University of Leicester                                  
Fergal Mullally, Princeton University                                 
Jay Holberg, University of Arizona                                    

Science Category: extrasolar planets 
 Observing Modes: IRAC Post-Cryo Mapping
  Hours Approved: 25.1 

Abstract:
We propose to obtain second epoch IRAC 4.5 micron images of 87 nearby white
dwarfs that were originally observed at the same wavelength during the first two
cycles of the Spitzer mission. By combining the data at these two epochs, we
will search for spatially resolved T and sub-T-type brown dwarf, and massive
planetary companions via common proper motions with their primaries. These
observations will comprise the deepest survey to date for wide substellar and
planetary-mass companions to white dwarfs in the solar neighborhood. Owing to
the known distance and age of each white dwarf, any companions identified in
this program would provide a benchmark for examining evolutionary models at ages
from a few 100 Myr to several Gyr. This survey will also provide the best
statistical limits yet on the frequency of such objects at white dwarfs and
their intermediate mass, main-sequence progenitors.