What implications are there for spotting nearby progenitors of Type Ias?
Judging by historical records, spectacular Type Ia supernovas within about ten thousand light years of the Earth occur about every five hundred years, at a rate only a few times lower than for nearby core-collapse supernovas. Progenitors for Type Ia supernovas in the Milky Way will be much harder to find if the merger scenario applies than if the accretion scenario applies, since two white dwarfs are thousands of times fainter than a Sun-like star, which in turn is much fainter than the progenitor of a core-collapse supernova. Depending on how well future astronomers do, mankind may be in for a surprise.
