Spitzer Space Telescope - General Observer Proposal #2300


Evolution of Gaseous Disks and the Formation of Giant and Terrestrial
Planets

Principal Investigator: John Carr
           Institution: Naval Research Laboratory

Co-Investigators: 
Joan Najita, National Optical Astronomy Observatory                   
David Hollenbach, NASA Ames Research Center                           
Uma Gorti, NASA Ames Research Center                                  

Science Category: circumstellar/debris disks 
 Observing Modes: IrsMap 
  Hours Approved: 30.0 

Abstract:
The remarkable diversity in the properties of the extrasolar planets
shows that planet formation can lead to a wide variety of outcomes,
including planetary systems very different from our own.  This
diversity raises a fundamental question:  What is the likelihood of
forming solar systems like ours?  One way to address this issue is by
studying the planet formation process as it occurs around nearby young
stars.  We propose to explore the gaseous component of planet-forming
disks from the onset of giant planet formation through the epoch of
the assembly of terrestrial planets (ages 1--10  Myr).  Our
observations, which will probe the gas content of disks over the range
of radii relevant to planet formation (< 10  AU), will address issues
that bear on the possibility of forming solar systems like our own.
The proposed observations will [1] determine the timescale available
to form giant planets and therefore identify dominant pathways for
giant planet formation;  [2] identify systems in which giant planets
may be forming through core accretion;  [3] measure the gas mass and
dissipation timescale in the terrestrial planet region of the disk, an
important factor in determining the likelihood of forming Earth-like
planets.