Sept. 9 Seminar: Reflected Light from Sand Grain in the Terrestrial Zone of a Protoplanetary Disk

Wednesday, Sept. 9, 2009, 4:15 PM, SSN 191

Reflected Light From Sand Grains in the Terrestrial Zone of a Protoplanetary Disk
Catrina Hamilton, Dickinson College

Abstract: In the standard model of terrestrial planet formation, the first step in the process is for interstellar dust to coagulate within a protoplanetary disk surrounding a young star, forming large grains that settle towards the disk plane.  I will present observations of a 3 million year old star, which show that grains have grown to about millimeter size or larger in the terrestrial zone (within ~ 3 AU) of this star.  The fortuitous geometry of the KH 15D binary system allows us to infer that, when both stars are occulted by the surrounding disk, it appears as a nearly edge-on ring illuminated by one of the central binary components.

{The Department of Geology and Astronomy seminars take place every Wed. during the fall semester in Schmuker Science Hall North, 730 N. Church St., West Chester PA, 19383, room 191. Refreshments are served at 4:00 pm, and thee discussion period begin promptly at 4:15 pm. Students, visitors, faculty and staff are strongly encouraged to attend. A campus is available here.}