The Chandrasekhar Limit - the maximum mass of a stable white dwarf star. (About 1.4 times the size of our sun.) White dwarves are slowly dying remnants of suns like ours, if left alone.
But if mass is added to one, and it gets more mass than the Chandrasekhar limit, it collapses further, into a neutron star or black hole, at the same time releasing a supernova explosion.
They estimate a third of all systems in our galaxy are binary or multiple, most of these are bigger than our sun, and half of them could harbor habitable planets. So the view in my image might actually not be that unusual.