‘Once in a lifetime event’: a rare chance to see an explosion in a dwarf star 3,000 light years away | Astronomy

In what is being called a “once-in-a-lifetime event,” light from a thermonuclear explosion in a star has been traveling toward Earth for thousands of years and will be here every day.

T Coronae Borealis (also known as T Cor Bor, T CrB and Blaze Star) will be as bright as the North Star (for those in the Northern Hemisphere).

Dr Laura Driessen, from the University of Sydney’s school of physics, said the Blaze Star will be as bright as Orion’s right leg for those in the southern hemisphere.

A recurring nova, T CrB becomes visible every 80 years after a thermonuclear explosion on the surface of a white dwarf about 3,000 light-years away.

The dwarf absorbs hydrogen from a neighboring red giant, and this causes an increase in pressure and heat that eventually causes the explosion.

Known as a nova (for “new”), it is expected to become visible anytime between now and September.

In the Corona Borealis, there is a dark spot. Astronomers and non-astronomers everywhere are monitoring the spot where the “new” star will appear. It will remain visible to the naked eye for about a week.

NASA has called it a “once-in-a-lifetime event.”

Driessen said the two stars are close enough that a gravitational pull results in the white dwarf absorbing material.

“It’s a binary system and every now and then there’s an explosion, so it’s a nova,” she said.

“When we think nova, we often think of supernova, which is when they explode at the end of their lives … there’s no going back from that. But a nova has a smaller surface explosion, based on this accretion, this accretion of material.”

The first recorded sighting of the Blaze Star was in 1217, when the abbot of Ursberg, Germany, saw “a faint star that for a time shone with great light,” says NASA.

It was last seen in 1946.

Driessen said the star is always changing, getting brighter and dimmer. But about 10 years before an outburst it starts to get a little brighter, before fading again in the months before the outburst.

“It’s not really going to be like clockwork, it’s about gathering material. So it’s not an exact number, but we have this early warning,” she said.

While the spectacular phenomenon has been observed before, Driessen said this is the first time it will be studied with modern technology.

“That’s why it’s so exciting. It will be the first where we get the information that we can access now, we have all these telescopes that we didn’t have 80 years ago,” she said.

NASA’s Fermi Gamma-ray Space Telescope, the James Webb Space Telescope and the National Radio Astronomy Observatory’s Very Large Array in New Mexico are just a few of the instruments that will track Blaze.

Fermi project scientist Dr Elizabeth Hays, who is also head of NASA’s Astroparticle Physics Laboratory, said typical nova events were far from over.

“This one will be very close, with many eyes on it, studying the different wavelengths and hopefully giving us clues to start unlocking the specific structure and processes involved,” she said.

“We’re looking forward to getting the full picture of what’s going on.”

NASA has a map of the Corona Borealis to help people determine where to look, and Driessen said software like Stellarium is also helpful. There are several free apps for viewing night sky maps.

Driessen said people should find the darkest area they can, as far away from a city or town as possible, and take binoculars for an even better view.

“Let your eyes adjust to the dark,” she said. “And it’s good to have a red torch. Put some cellophane on top so it doesn’t spoil your night vision. And don’t look at your phone.”