Cosmic explosion will soon be visible

A rare stellar explosion will soon result in a bright new “star” appearing for a few days in Canada’s night sky.

The eruption, known as a “nova,” will occur in the T Coronae Borealis system — a binary system of two stars 3,000 light years away. While normally invisible to the human eye, it will appear as bright as the North Star during the phenomenon, according to NASA.

“T Coronae Borealis is thought to brighten about once a century or so, and hasn’t been seen with the naked eye” since1946, said Heidi White, an astrophysicist with the Université de Montréal and University of Toronto. “So it’s something of a oncein-a-lifetime event!”

We aren’t yet sure exactly when it will occur, although it’s expected sometime before September. Astronomers are closely watching the system for signs of eruption: “We’ll let you know when and where to look,” White said.

The “new star” will be visible for several days to the naked eye — and just over a week for those with binoculars — before it dims for potentially another 80 years, according to a NASA blog post.

The agency says it will appear as a bright light in the Corona Borealis constellation, a semicircular arc wedged between the more recognizable Bootes and Hercules constellations.

John Percy, a professor emeritus of astronomy at the University of Toronto Mississauga, explained the constellation “goes pretty much overhead in the evening, in the spring or summer for us here (in Ontario).

“… It really is in the shape of a little crown, and the Nova would be within that crown. So, particularly if you have binoculars, I think it would be really interesting to look at,” he said.

According to NASA, the rare event is one of just five recurring novas in our galaxy.

Percy explains this is able to happen because T Coronae Borealis is made of two stars — a “white dwarf” (the remains of a dead star) and a “red giant” (a dying star that’s chewed through its core’s hydrogen supplies). “Material gets sucked across by gravity and builds up on the surface of the white dwarf star.”

Over time, the white dwarf’s shallow, dense atmosphere heats up the matter enough to start a runaway “nuclear fusion eruption — the star suddenly brightens by many hundreds of times,” Percy said.