UK space scientists watching a burping star say it is on the brink of sparking the biggest explosion in the galaxy.
The star, called RS Ophiuchi, has been closely studied since amateur stagazers saw it flare up in February. That belch – the sixth observed in the star in the past 108 years – was equal to a nuclear bomb the size of the Earth going off. The star became visible to the naked eye as it became 1,000 times brighter than normal.
Now professional astronomers say that was just a foretaste of the catastrophic explosion that is to come. They predict that the star will blow itself to bits in a supernova explosion not seen in our own Milky Way for 434 years. During its spectacular death throes it will become five billion times brighter than the sun and as bright as all the other stars in the galaxy combined.
Tim O’Brien, of Jodrell Bank in Cheshire, led an international team that used radio telecopes around the world to observe the shock wave following this year’s nuclear blast. They recorded it travelling at more than 1,000 miles per second through space.
Other astronomers used the Rossi X-ray Timing Explorer satellite to show that the star is set to become a Type 1a supernova. They believe RS Ophiuchi is a double star with a white dwarf orbiting a red giant. The smaller star, stripping material away from its companion, is on the verge of reaching a critical mass at which point it will blow itself to pieces.
Experts say the blast could happen at any time. In fact there is a chance it has already happened as the star lies 5,000 light years from Earth and so its light takes that length of time to reach us. Image by PPARC/David Hardy