In what’s called a “once-in-a-lifetime event,” light from a thermonuclear explosion on a star has been traveling toward Earth for thousands of years and could arrive here at any moment.
T Coronae Borealis (also known as T Cor Bor, T CrB, and the Blaze Star) will be as bright as the North Star (for those in the Northern Hemisphere).
According to Dr Laura Driessen from the University of Sydney’s Department of Physics, the Blaze Star will appear as bright to people in the southern hemisphere as the right foot of Orion.
T CrB is a recurring nova that becomes visible about every 80 years after a thermonuclear explosion on the surface of a white dwarf about 3,000 light-years away.
The dwarf sucks in hydrogen from a nearby red giant, creating a buildup of pressure and heat that ultimately causes the explosion.
This nova (for ‘new’) is expected to be visible from now until September.
In the Corona Borealis there is a dark spot. Astronomers and non-astronomers all over the world are watching that spot, where the “new” star will appear. It will be visible to the naked eye for about a week.
NASA calls it a “once-in-a-lifetime event.”
According to Driessen, the two stars are so close together that the white dwarf is sucking in matter through gravity.
“It’s a binary system and every now and then there’s an outburst, so it’s a nova,” she said.
“When we think of nova, we often think of supernova, which is when they explode at the end of their life … there’s no going back. But a nova has a smaller surface explosion, based on this accretion, this collection of material.”
The first recorded sighting of the Blaze Star was in 1217, when the Abbot of Ursberg in Germany “saw a faint star which shone for a time with great brightness,” according to NASA.
It was last seen in 1946.
Driessen said the star is always variable, brightening and dimming. But about 10 years before an explosion it starts to brighten a little, only to fade again in the months before the explosion.
“It’s not really going to be a clockwork thing, it’s going to be a matter of material buildup. So it’s not an exact number, but we have this early warning,” she said.
Although this spectacular phenomenon has been observed before, Driessen says this is the first time it has been studied using modern technology.
“That’s why it’s so exciting. It will be the first one where we get the information that we have access to 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 some of the instruments that will keep an eye on the Blaze.
Dr. Elizabeth Hays, a Fermi project scientist and head of NASA’s Astroparticle Physics Laboratory, said typical nova events were far away.
“This will be really close, with many eyes on it, studying the different wavelengths and hopefully giving us data to unravel the structure and specific processes involved,” she said.
“We can’t wait to get a full picture of what’s going on.”
NASA has a map of the Corona Borealis to help people decide where to look, and Driessen said software like Stellarium is also useful. There are several free apps for viewing maps of the night sky.
According to Driessen, people should seek out an area that is as dark as possible, as far away from the city or village as possible, and take binoculars with them for an even better view.
“Let your eyes adjust to the dark,” she said. “And it’s good to have a red flashlight. Put a piece of cellophane over it so it doesn’t mess up your night vision. And don’t look at your phone.”