Spitzer Space Telescope - General Observer Proposal #40224


The pre-supernova mass-loss behaviour of Red Supergiants 

Principal Investigator: Ben Davies
           Institution: Rochester Institute of Technology

     Technical Contact: Ben Davies, Rochester Institute of Technology

Co-Investigators: 
Don Figer, RIT                                                        
Jacco van Loon, Keele University, UK                                  
Joel Kastner, RIT                                                     

Science Category: evolved stars/pn/sne 
 Observing Modes: IrsStare 
  Hours Approved: 17.1 

Abstract:
The mass lost by massive stars as they pass through the Red Supergiant (RSG)
phase is a crucial determinant in the terminal mass of the star, the nature of
the resulting supernova explosion and the stellar end-state. However, up until
now studies of this quantity have been problematic, owing to the low numbers of
known RSGs and the difficulty of observing in the mid-IR. Here, we capitalize on
the recent discoveries of two remarkable Galactic clusters containing
unprecedented numbers of RSGs, and use the capabilities of {it Spitzer} to
undertake a comprehensive and unique study of the pre-SN mass-loss of massive
stars. We will use {it Spitzer/IRS} observations in conjunction with
state-of-the-art dust models to provide the first quantitative investigation of
the mass and composition of the pre-SN ejecta as a function of age and
metallicity. This study is vital in determining the mass-loss behaviour of RSGs
in particular, and the nature of supernova progenitors in general.