If you keep an eye on the night sky in the coming weeks and months, you might see something new. It will shine as brightly as Polaris, the North star, for no more than a week before fading back into darkness.
This temporary beacon is T Coronae Borealis, often referred to as T CrB. This is a nova, a nuclear explosion that erupts from the pale corpse of a dead star. Some people may have seen it before — the same magnificent sight graced our skies nearly 80 years ago — and future generations will probably see it again in another 80 years.
For near worlds, a nova would result in disaster. But for stargazers in our world, some 3,000 light years from us, this “is an exciting and exciting cataclysmic event to come,” said Bradley Schaefer, an astrophysicist at Louisiana State University.
Here’s everything you need to know about this event: what it is, when it will appear and where you can see it.
What is nova?
There are more than 400 known novae in the Milky Way Galaxy. They are caused by an explosive pairing between a normal type of star — for example, a primary star like Earth’s sun or an elephant red giant — and a white dwarf, the burning stellar core left over after the death of a star. The two are gravitationally bound friends destined to unleash a fiery eruption in the cosmos.
White dwarfs are relatively small, but they are also so dense that their intense gravitational pull steals hydrogen-rich material from nearby regular stars. The explosive material fell onto the white dwarf’s surface and, after a while, began to build up, squeezing its lower layers and increasing its temperature.
Eventually, the compressed material “passes the flame temperature of hydrogen,” says Dr. Schaefer. It flared up, increasing the temperature of the accumulated matter even further. After a certain point, a continuous nuclear reaction begins, triggering an apocalyptic explosion.
“This nova is basically a hydrogen bomb,” said Dr. Schaefer.
But don’t confuse a nova with its louder sibling, the supernova, which permanently destroys a star and throws off its outer layers in a rage. Once the nova’s nuclear remains fade, the cycle begins again, with the white dwarf once again ejecting its way to the next explosion.
What is T Coronae Borealis, and how do we know when it will explode?
T CrB is a nova that occurs when a white dwarf peels off enough of the outer layers of a red giant star that is about 74 times more massive than our sun.
The nova last exploded in 1946. Astronomers also observed its eruption in 1866, and historical reports indicate that it was seen in 1787 and 1217.
Most novae have explosion cycles that last thousands of years. However, T CrB is impatient — a voracious eater of its giant red star’s fuel. Previous observations showed that it explodes once every 80 years, making it a repeat nova — one that explodes at least once every century.
Previous observations of T CrB also showed that the nova ignited and wiggled itself very irregularly in the years leading up to its eruption, and it appears to be no different this time: Its activity over the past decade or so suggests that it is preparing to explode in the near future, which will occurring any time between now and September.
Where in the night sky will I be able to see it?
T CrB will appear in the constellation Corona Borealis, which borders Hercules and Bootes. When it “explodes,” it will shine as bright as the North Star and will be visible for several days,” said Bill Cooke, Chief of the Meteoroid Environment Office at NASA’s Marshall Space Flight Center in Huntsville, Alabama.
“You will see new stars in the sky,” he added, visible to the naked eye.
Do not miss. “This is a once-in-a-lifetime event,” said Dr. Cooke. “How often can people say they have seen a star explode?”
2024-03-08 14:00:48
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