The greatest puzzle in the field of stellar evolution is how stars and attendant planetary systems are formed from their parent interstellar clouds. In previous NSF-supported work, the Principal Investigator (PI) has shown that the circumstellar clouds remaining around half of all the young ("T Tauri") stars are massive enough for them to evolve into planetary systems such as our own solar system. With a new three-year award from the NSF, the PI will continue these studies with an emphasis on the role of the circumstellar disks around T Tauri stars in accreting and expelling mass from the stellar systems. The PI will also attempt to correlate the properties of young stars and the properties of their interstellar clouds. Most of the award will be used to support a postdoctoral fellow, a graduate student, and two undergraduates on this project.
