Abstract.
This article discusses protostellar disk dispersal due to
photoevaporation by ultraviolet and X-ray photons from the central
star. The current theoretical understanding of disk dispersal is
summarised and observational constraints are discussed. Disk
lifetimes due to photoevaporation are typically ∼ a few million
years and depend on stellar mass, radiation field, disk viscosity,
and dust evolution.
Key words:stars: formation -- protoplanetary disks; accretion:
accretion disks