Spitzer Space Telescope - Directors Discretionary Time Proposal #528


Monitoring the Variability of the HD69830 Zodiacal Cloud

Principal Investigator: Charles Beichman
           Institution: NExScI

     Technical Contact: Charles Beichman, NExScI

Co-Investigators: 
Geoff Bryden, JPL
Casey Lisse, JHU
Mary Wyatt, Cambridge Univ.

Science Category: debris disks
 Observing Modes: IrsStare
  Hours Approved: 1.5

Abstract:
Examination of our Spitzer/IRS data from 3 epochs (two in 2007 and 
the discovery observations  in 2004) show significant changes in the 
small grain content of the debris disk surrounding the star HD69830. 
The dynamical time scale for this disk is of  order of 1 yr and the 
existence of 3 planets within 1 AU, where the debris cloud is located,  
makes the continuous disruption of large solid bodies likely. HD69830 
is the premier laboratory for disk-planet interactions. We request 
1.5 hours of IRS/LoRes time to extend the time baseline to allow us 
to monitor this variability.