Why can the lives of close binary stars differ from those of single stars?
Closed binary star systems have the capability to supernova.
In a binary star system the larger star evolves in to a red giant and then collapses into a white dwarf.
Some time later the second star will become a red giant. If the stars are close enough together, as in a closed binary system, the white dwarf will accumulate material from the red giant.
When the white dwarf accumulates enough material to approach the Chandrasekhar limit of 1.44 solar masses it will start to collapse. At this point carbon fusion will start which consumes a significant amount of the star's mass in a matter of seconds.
This causes a type 1a supernova explosion..