Spitzer Space Telescope - General Observer Proposal #41019


Catching the Post-Outburst State of the Erupting Star V1118 Ori

Principal Investigator: Marc Audard
           Institution: Observatoire de Geneve

     Technical Contact: Marc Audard

Co-Investigators:

Manuel Guedel, Paul Scherrer Institute
Stephen Skinner, University of Colorado
Guy Stringfellow, University of Colorado 
Kevin Biggs, Paul Scherrer Institute
Frederick Walter, SUNY Stony Brook
Edward Guinan, Villanova University
Ryan Hamilton, New Mexico State University
                           
Science Category: young stellar objects 
 Observing Modes: IRAC Mapping, IRS Staring, MIPS SED
  Hours Approved: 2.7

Abstract:
We propose to catch the post-outburst state of the young accreting star 
V1118 Ori with Chandra and Spitzer. V1118 Ori underwent an optical 
outburst in January 2005 and has now returned to a ``quiescent'' state. 
Our X-ray monitoring observations have shown that the X-ray spectrum 
softened after the outburst, maybe due to changes in the magnetic 
structure near the star as a result of the increased accretion load. 
Our long-term monitoring indicates that the X-ray flux correlates with 
the optical flux, a signature that accretion can impact the X-ray 
emission of outbursting young stars. We propose also to obtain the 
post-outburst spectral energy distribution in the mid-infrared with 
Spitzer. We will compare the new data with those taken by us in the early 
phase of the outburst.