Every star that hangs upon the evening firmament will one day die, its lights snuffed and its fires cooling in the dwindling cosmic end times.

We don’t always know when, but for a binary star system around 150 light-years from Earth, a precise time of death has now been discovered. Some 23 billion years from now, the two white dwarf stars are destined to smash together.

At least, they would, if not for the fact both will be taken out before this fated merger by a spectacular explosion – a Type Ia supernova, one of the measuring sticks against which we gauge distance in the Universe.