In the inky blackness of deep space, 25,000 light years from Earth, the blue supergiant [SBW2007]-1 is churning with energy.

The star, which was once twenty times larger than the Sun, is preparing to go supernova — creating an enormous explosion that’ll eject its core at speeds of up to 30,000 kilometres per second into the wispy nebula that surrounds it.

1987A supernova remnant near the centre. Image credit: NASA.

Well probably, anyway. Astronomers who’ve been studying it have noted striking similarities with another star that went supernova —Sanduleak -69° 202, which became known as SN1987N when we spotted it exploding.

The European Space Agency (ESA) explains on its website that early images of that star show identical rings of the same size and age, travelling at similar speeds, with the same brightness, located in similar regions of space. “In this way SBW1 is a snapshot of SN1987a’s appearance before it exploded,” says the ESA.

SN1987a’s 15-year-long explosion

Add all those similarities together, and astrophysicists reckon that it seems pretty likely that [SBW2007]-1, or SBW1 as its known to its friends, is going to go supernova in exactly the same way.

The question is when. It could be tomorrow, or it could be in hundreds or even thousands of years. “At a distance of more than 20,000 light-years it will be safe to watch when the supernova goes off.” says the ESA. “ If we are very lucky it may happen in our own lifetimes.”

On stellar timescales, there isn’t a whole lot of difference between the two, despite the relative youth of most blue giants. So don’t wait up.