Spitzer Space Telescope - General Observer Proposal #3469


Infrared observations of an eclipsing binary T Tauri star

Principal Investigator: Eric Agol
           Institution: University of Washington

Co-Investigators: 
Jacqueline Kessler-Silacci, University of Texas                       
Catrina Hamilton, Rice University                                     

Science Category: circumstellar/debris disks 
 Observing Modes: IracMap 
  Hours Approved: 1.2 

Abstract:
The eclipsing T Tauri star KH 15D has a period of 48 days with
eclipses of 3.5 magnitudes lasting for 20  days.  The properties of
this star can be explained if it is an eccentric binary T Tauri star
with semi-major axis 0.28 AU and eccentricity 0.7 surrounded by a
precessing ring of dust at 2-3 AU which is gradually eclipsing both
stars.  We wish to make infrared observations of this system to (a)
constrain the inclination and width of the ring;  (b) constrain the
size of the dust within the ring to confirm evidence for grain-growth;
(c) look for the presence of PAH, silicates or other mid-infrared
features which may constrain the presence of smaller dust grains
within the system.  We will use our observations to measure the
surface density of the edge of the ring which may be shaped by a
shepherding planet.