Spitzer Space Telescope - General Observer Proposal #50360


A deep look at the evolution of 4-10 Myr old disks in Orion OB1

Principal Investigator: Cesar Briceno
           Institution: Centro de Investigaciones de Astronomia (CIDA)

     Technical Contact: Cesar Briceno, Centro de Investigaciones de Astronomia (CIDA)

Co-Investigators: 
Nuria Calvet, University of Michigan                                  
Jesus Hernandez, University of Michigan/CIDA                          
James Muzerolle, Steward Observatory, University of Arizona           
Catherine Espaillat, University of Michigan                           
Lee Hartmann, University of Michigan                                  

Science Category: circumstellar/debris disks 
 Observing Modes: IracMap MipsScan 
  Hours Approved: 29.6 

Abstract:
We propose to obtain deep IRAC/MIPS observations of recently discovered
populations of stars with ages 4-10 Myr in the Orion OB1 association. Many of
the young members in these regions are concentrated in distinct stellar
aggregates, with differing ages, but presumably sharing a common origin. Among
them is the 25 Ori group, by far the most populous 10 Myr old sample yet known
within 500 pc. Our ongoing large-scale survey of the Orion OB1 star-forming
region has allowed us to find these elusive populations and secure the
photometric and spectroscopic data needed to fully determine the stellar and
accretion properties of these objects, from ~3 solar masses down to the lowest
mass stars at the substellar boundary. The proposed Spitzer IRAC/MIPS
observations, combined with existing ground-based optical and near-infrared
data, will yield spectral energy distributions for characterizing protoplanetary
disks, as a function of stellar mass and environment. This will enable us to
discern the overall trends in circumstellar disk evolution during the important
age range 4-10 Myr, when planet formation and disk dissipation are expected to
occur, thus providing the best constraints yet for theoretical models in this
pivotal stage.