It only ignites approximately every 80 years
Astronomers are preparing for a dazzling celestial show that only happens approximately every 80 years.
In 1946, 15-year-old school boy Michael Woodman, a keen amateur astronomer spotted a bright star in the night sky.
“There was the constellation of Corona Borealis, but in the ring of the Corona, the second star down was bright – very bright,” he recalled.
He wrote to the Astronomer Royal the next day to tell them what he saw and was surprised by their response.
Woodman had witnessed a rare celestial event that briefly dazzled the heavens.
The Royal Astronomer confirmed that he was the first person in the country to have seen this event.
The now 94-year-old had spotted a star system, about 3,000 light years away, called T Corona Borealis – or T Cor Bor for short – exploding into brightness, becoming visible in the night sky for a few short days.
Now a whole new generation of stargazers are scanning the skies again because scientists believe T Cor Bor ignites about every 80 years or so.
On a crystal clear night, in the Dark Skies Reserve of Bannau Brycheiniog, also known as the Brecon Beacons, astronomers have been setting up their telescopes.
Dr Jenifer Millard from Fifth Star Labs said: “T Cor Bor is dim at the minute – it’s magnitude 10, well below what you can see with the naked eye. It is only going to be visible to the naked eye for a couple of days.
“Of course, if you’ve got a small pair of binoculars or a small telescope, you’ll be able to see it for a little bit longer because you’ve got that magnifying tool. But I do think that it is the short stint in the sky that makes it really special.”
To find the area of sky where it should appear, she advises to first locate the plough and follow its handle to Arcturus.
To the west of this star is the curved constellation of Corona Borealis, made up of seven stars, and where T Cor Bor will at some point light up.
The astronomical phenomenon is caused by the interaction between two stars orbiting each other.
A small white dwarf, which is a dead star, and a much larger red giant – a star that’s reaching the end of its life.
The white dwarf has an immense gravitational pull which steals material away from its larger neighbour.
Dr Jane Clark from the Cardiff Astronomical Society explains: “The gravity on the surface of the white dwarf is a million times the gravity we feel on Earth, so if we stood on it, we would be crushed instantly.”
The material it steals from the other star gets crushed and compressed until it eventually triggers a nuclear explosion which releases a huge amount of energy – a process known as going nova.
It is at that point that a bright light appears in the sky.
Astronomers think this process happens on repeat, with an outburst from T Cor Bor occurring about every 80 years, however there have been a few false alarms over the years and very few records of its appearance.
