Just a little more astronomical nerdiness. It probably wasn't a supernova, but if it was, then it also doesn't represent a star dying now but rather one dying a long time ago. The Milky Way galaxy is about 100,000 light years in diameter, which means that the light from that star, if it was a star, could take tens of thousands of years to reach the earth. Of course if it was the ISS then whatever was happening with it was much more recent.