Time Variability of the Dust Sublimation Zones in Pre-Main Sequence Disk Systems M.L. Sitko (U Cincinnati & Space Science Institute) , R.W. Russell, D.K. Lynch, R.J. Rudy, S.M. Mazuk, C.C. Venturini (The Aerospace Corporation), et al.

PMS disk systems are places where planets are born In the past, they were treated as static systems, where one model was expected to “explain all” The photometrically-determined spectral energy distributions were at odds with those predicted by NIR interferometry Hubble coronagraphic image of HD 163296 disk

There is no single-epoch model that is applicable at all times In fact: The inner edges of such disks are variable - interferometry and spectrophotometry need to be obtained in tandem There is no single-epoch model that is applicable at all times The variability points to some interesting consequences Changes in the emission of HD 163296 can be traced from 0.8 to13 m. These localize them to the inner edge of the dust disk where T~1000 K The bulk of the data used to localize the nature of the IR variability was obtained on the IRTF with BASS.

The time variations in the IR emission from HD 31648

Such variability may also signal the presence of planets: The variability may point to important disk behavior that affects the processing of grains at the inner edge: In January 2008, Setiawan et al. announced the detection of a planet at the inner edge of the disk in TW Hya (using Doppler measurements). Repeated heating & cooling at the inner edge will tend to anneal amorphous grain material into crystalline grains The bulk of the data used to localize the nature of the IR variability was obtained on the IRTF with BASS.