Binary Paths to Type Ia Supernovae Explosions: The Highlights
  This Symposium was focused on the hunt for the progenitors of Supernovae of
Type Ia. Is there a main channel for the production of SNeIa? If so, are these
elusive progenitors Single Degenerate or Double Degenerate systems? Although
most participants seemed to favour the Single Degenerate channel, there was no
general agreement on the type of binary system at play. An observational puzzle
that was highlighted was the apparent paucity of Super-Soft Sources in our
Galaxy and also in external galaxies. The Single Degenerate channel (and as it
was pointed out, quite possibly also the Double Degenerate channel) requires
the binary system to pass through a phase of steady nuclear burning. However,
the observed number of Super-Soft sources falls short by a factor of up to 100
in explaining the estimated birth rates of SNeIa. Thus, are these Super-Soft
sources somehow hidden away and radiating at different wavelengths or are we
missing some important pieces of this puzzle that may lead to the elimination
of a certain class of progenitor? Another unanswered question concerns the
dependence of SNeIa luminosities on the age of their host galaxy. Several
hypotheses were put forward, but none was singled out as the most likely
explanation.
  It is fair to say that at the end of the Symposium the definitive answer to
the vexed progenitor question remained is well and truly wide open.
