Spitzer/MIPS 24 micron Detection of Photoevaporating Protoplanetary   Disks
  We present 24 micron images of three protoplanetary disks being photoevaporated around high mass O type stars. These objects have ``cometary'' structure where the dust pulled away from the disk by the photoevaporating flow is forced away from the O star by photon pressure on the dust and heating and ionization of the gas. Models of the 24 micron and 8 micron brightness profiles agree with this hypothesis. These models show that the mass-loss rate needed to sustain such a configuration is in agreement with or somewhat less than the theoretical predictions for the photoevaporation process. 
Z. Balog (1 and 2), G. H. Rieke (1), K. Y. L. Su (1), J. Muzerolle   (1), E. T. Young (1) ((1) Steward Observatory Univ. of ...