Finding Supernova Ia Progenitors with the Chandra X-ray Observatory
  We examine pre-supernova Chandra images to find X-ray luminosities of type Ia supernova progenitors. At present, we have one possible direct detection and upper limits for the X-ray luminosities of a number of other supernova progenitors. The method has also yielded a possible detection of a X-ray binary Wolf-Rayet system as the progenitor of a type Ib supernova. 
Mikkel T.B. Nielsen, Gijs Nelemans, Rasmus Voss
astro-ph.HE