Spitzer Space Telescope - General Observer Proposal #60160


An Exploration of Unique Mid-Infrared Variability around Transition Disks and
Class I stars in IC 348

Principal Investigator: James Muzerolle
           Institution: University of Arizona

     Technical Contact: Kevin Flaherty, Steward Observatory, U. Arizona

Co-Investigators: 
Zoltan Balog, Steward Observatory                                     
Kevin Flaherty, Steward Observatory                                   
Robert Gutermuth, Smith College                                       
William Herbst, Wesleyan College                                      
S. Thomas Megeath, University of Toledo                               

Science Category: young stellar objects 
 Observing Modes: IRAC Post-Cryo Mapping
  Hours Approved: 21.5 

Abstract:
We propose to obtain repeated 3.6 and 4.5 micron observations of IC 348 focusing
on young stellar objects that show evidence of unique and unusual mid-infrared
variability. Previous Spitzer observations have found variations in the
mid-infrared flux in as little as a day along with a strong wavelength
dependence. We focus on a handful of T Tauri stars that exhibit spectral energy
distributions similar to transition disks and two class I stars that show the
largest 24 micron variability of any young stellar object in the cluster. In the
T Tauri disks the variability may be related to a change in the scale height of
the inner edge of this disk. Repeated observations covering a range of
timescales from hours to weeks will help to constrain the physical mechanism
leading to this variable scale height. For the class I stars, our proposed
observations will help to constrain the details of the envelope/disk structure
and variable accretion. These data will provide an essential tool for
understanding stellar mass build up, accretion and planet formation.