Southern Canadian skies have seen some exciting sights so far this year, including a spectacular solar eclipse in April and a rare aurora borealis display in May. And this summer, an exploding star visible to the naked eye may be on its way.
“Nova explosions only happen once every 80 years, so this could be a once-in-a-lifetime opportunity to observe it.” To this NASA blog.
The blog explains that T Corona Borealis, a star system in the Milky Way galaxy about 3,000 light-years from Earth, last exploded in 1946, and astronomers believe it will explode again by September 2024.
Of course, this stellar explosion would be dwarfed by that of another much closer and more massive star, Betelgeuse, which some believe may be poised to go nova or even supernova.
Now, to put it into perspective, astronomers are much more confident about the timing of T Corona Borealis’ impending outburst than they are about Betelgeuse, which could be tomorrow or it could be (tens of) thousands of years from now.
T Coronae Borealis said Elaina Hyde, assistant professor in the Department of Physics and Astronomy at York University and director of the University’s Alan I. Carswell Observatory “This is a pretty interesting star, and we’re actually observing it now with our observatory to see what happens,” said the Toronto researcher.
“The observatory has a student-run crew and a one-metre telescope, the largest on a campus in Canada, so with a few hours of observing each night we hope to be lucky enough to capture part of the light curve,” he said.
The star has been nicknamed the “Fire Star,” she said, adding, “It’s actually two stars orbiting each other, with one of them gathering material and exploding periodically — a so-called nova.”
She explains that the two stars are a red giant and a white dwarf, with the dense white dwarf basically pulling material from the expanding red star.
And every now and then, or more precisely every 80 years, it will “reach a flashpoint and cause a runaway thermonuclear explosion.” This NASA primer.
The original white dwarf survives the explosion and begins to collect material from the red giant, then explodes again.
Hyde explained that the sun is destined to go through both the red giant and white dwarf phases, but that won’t happen until all of the normal hydrogen fuel in the sun’s core has fused together, about 5 billion years from now. According to this introduction The life cycle of the sun Space.com.
Betelgeuse, on the other hand, is an entirely different type of star and is heading towards a different type of explosion: a supernova.
This isn’t just a red giant, it’s a red supergiant, so if it existed in our solar system it would envelop all the planets, right up to Jupiter. This NASA explanation.
Unlike the much smaller Sun, which can essentially fuse nothing after it runs out of hydrogen and helium, supergiants can continue to fuse heavier elements “including carbon, oxygen, calcium, and eventually iron,” he said. This NASA explanation.
But the party ends there: iron doesn’t fuse, so there’s basically nothing to stop a massive star from falling on itself and recoiling violently, briefly creating an explosion that burns brighter than the entire galaxy it resides in. NASA’s Primer on Big Stars.
And if it does indeed explode, scientists predict that its brightness could briefly make the night sky equivalent to that of a half or full moon.
It is already one of the brightest stars in the night sky. According to this NASA article:It is large in size and relatively close at a distance of about 450 light years.
The star has been in the news in recent years due to unusual dimming events that have some experts worried it may be on the verge of exploding, but scientists don’t know exactly what stage it is at and can’t predict its demise with certainty, but the general consensus is that it probably won’t happen anytime soon.
The T CRB, on the other hand, is invisible to the naked eye, and Hyde says that if it goes into a nova explosion, its brightness will temporarily be slightly less than Betelgeuse’s current brightness.
“You’d have to look for it in a pretty dark sky,” she said, adding that what’s really exciting is “suddenly seeing something new.”
