title: Accretion onto Young Stars

authors: Gregory J. Herczeg

abstract: Most of the mass in a young proto-planetary disk drains onto the central star.  When accretion slows near the end of the disk lifetime, photo-evaporation and planet-disk interactions may change the disk structure and cause the eventual dispersal of the disk.  The presence of gas in proto-planetary disks, which is best probed through accretion processes, has been suggested as a means to diagnose the process that may produce holes and gaps in transition disks.  In this talk, I will review our current understanding of magnetospheric accretion, describe how accretion is measured, and evaluate the presence of accretion onto transition disks.  I will also present recent results on the radiation field produced by accretion processes and new probes of how the stellar radiation affects the chemical and temperature structure of the disk.