James MUZEROLLE : Steward Observatory, University of Arizona
Transition Disks from a Spitzer Imaging Survey of Young Clusters
I will review recent results on transition disks identified from a Spitzer survey of young star forming regions and stellar clusters. We have found a fair number of candidates lacking excess emission shortward of about 10 microns suggestive of large inner disk holes either partly or completely cleared of small dust grains. These transition disks appear across the stellar mass spectrum, including brown dwarfs, and at all ages from 1-10 Myr, including the youngest embedded regions. Many are actively accreting gas while some appear to be quiescent. The sample is now statistically robust enough to put strong constraints on disk clearing mechanisms, including the possibility of inside-out planetesimal growth and gas giant formation.Last modified: Sun Jul 9 18:04:51 2006