Spitzer Space Telescope - General Observer Proposal #3362


In the BAG:  Spitzer observations of the `born-again' phenomenon

Principal Investigator: Aneurin Evans
           Institution: Keele University

Co-Investigators: 
Robert D. Gehrz, University of Minnesota                              
Charles E. Woodward, University of Minnesota                          
Elisha Polomski, University of Minnesota                              
Mark T. Rushton, Keele University                                     
Jacco Th. van Loon, Keele University                                  
Barry Smalley, Keele University                                       
Sumner G. Starrfield, Arizona State University                        
Joachim Krautter, Landessternewarte, Heidelberg                       
Thomas R. Geballe, Gemini North                                       
Stewart S. P. Eyres, University of Central Lancashire                 
Victor Tyne, Keele University                                         
R. Mark Wagner, University of Arizona                                 

Science Category: evolved stars/pn/sne 
 Observing Modes: IracMap IrsMap IrsStare MipsScan 
  Hours Approved: 16.9 

Abstract:
We will use the unique capabilities of Spitzer to probe the
environments of 'born-again' objects.  These are evolved stars -
typically of solar mass - which are on their way to becoming white
dwarfs but reignite helium and retrace their evolution back up to the
giant region of the H-R diagram.  Spitzer will enable us to search for
faint, extended far-IR fossil shells, to map out their planetary
nebulae and (by combining with ongoing ground-based optical and
near-IR observations), to determine the spectral energy distribution
(SED) from the visible to the far-IR.  Spitzer will also allow us to
observe one of these systems in M31 and, because it is at a known
distance, we will be able to determine unambiguously the energetics of
one of these objects.  These observations will help us to understand
the major upheaval, only recently discovered, that is undergone by
perhaps as many as 20% of solar mass stars, and hence provide us with
a glimpse of what the Sun could have in store.