PI: Joan Najita, NOAO, firstname.lastname@example.org
Address: 950 N. Cherry Ave., Tucson, AZ 85719, USA
CoI: James Muzerolle, STScI
CoI: Greg Doppmann, Keck Observatory
CoI: Stephen Strom, NOAO
Title: Transition Objects: Photoevaporation, Grain Growth, or Planet-Forming Disks?
Abstract: Transition objects are an interesting class of young stellar objects whose SEDs indicate that significant disk evolution has occurred. Although the SEDs are commonly interpreted as a sign of giant planet formation, grain growth and disk photoevaporation have been put forward as alternative explanations. We propose to use stellar accretion rates as a tool to distinguish among these possibilities, since disk evolution theories make very different predictions for the impact of these processes on the stellar accretion rate. We will build on our earlier study of the Taurus star forming region by measuring stellar accretion rates for transition objects and control samples of normal T Tauri stars in populations both younger and older than Taurus. Our observations will constrain the timescales for the onset and duration of giant planet formation, thereby providing direct constraints on physical pathways for giant planet formation. Finally, as stellar accretion rates are a fundamental diagnostic for many aspects of star and planet formation, there is significant legacy value for our measurements beyond the goals of this study.
National Optical Astronomy Observatory, 950 North Cherry Avenue, P.O. Box 26732, Tucson, Arizona 85726, Phone: (520) 318-8000, Fax: (520) 318-8360