Betelgeuse brighter than 140%
One of the brightest stars in the night sky is surprisingly bright, prompting speculation that it may soon explode as a supernova. Can we really expect such a dazzling cosmic drama?
The star in question is Betelgeuse, a giant red star that sits on Orion’s left shoulder. About 650 light years from Earth, Betelgeuse is the 10th brightest star in the night sky. However, according to Betelgeuse Status, a Twitter account that tracks the star’s behavior, Betelgeuse has now increased to more than 140% of its ‘normal’ brightness, making it seventh in the brightest star rankings.
Betelgeuse is a red giant, a massive star that has expanded hundreds of times its original body by burning all the hydrogen fuel in its core. Astronomers believe that the star is currently fusing helium into carbon and oxygen. This stage lasts tens of thousands to hundreds of thousands of years, a fraction of a second in the long life of a star, and immediately leads to a supernova explosion after this period.
Betelgeuse’s strange behavior dates back to 2019. From then on, Betelgeuse brightened and then darkened repeatedly, creating an unusual situation. So some astronomers and astronomers have speculated that Betelgeuse’s dramatic death may be imminent.
Supernova explosions occur in our galaxy at a rate of about one every 100 years, but strangely enough, none have occurred since two supernova explosions observed in succession by astronomers Tycho Brahe and Johannes Kepler 400 years ago. So, in the world of astronomy, there is even a joke that supernovae explode only when great astronomers are present.
If Betelgeuse explodes as a supernova, humanity will see the closest supernova explosion in 400 years, and the explosion will be so huge that Betelgeuse will be visible even during the day.
If Betelgeuse exploded at a distance of several tens of light years from Earth, the entire solar system as well as Earth would disappear overnight, but luckily it is 650 light years away, so it won’t the Earth is directly damaged by the supernova explosion. .
Betelgeuse gets weird after ‘Daeamjeon’
Betelgeuse is a variable star whose brightness changes from time to time. For over 100 years, astronomers have seen Betelgeuse fall to about half its peak brightness every 400 days, and then shine again. However, in December 2019, unexpectedly, the star became dimmer than seen before, reaching a minimum brightness of 2.5 times less than normal.
Later it was found that the cause of this event, known as the Great Dimming, was a huge cloud of dust obscuring our view of the stars. Dust clouds like this are the result of huge amounts of material expelled from the star’s interior.
After a while, Betelgeuse returned to its normal brightness, but not what it used to be after the Great Dark War. The variable light cycle of 400 days has been reduced to 200 days, which is half that, and the phenomenon that the bright period increases is exciting stargazers. However, the interpretation of astronomers is rather negative to the possibility of a supernova explosion.
“Our best modeling shows that Betelgeuse is in the process of burning helium to carbon and oxygen in its core,” said Morgan McLeod, a postdoctoral fellow in theoretical astrophysics at Harvard University. That means 100,000 years.”
He is the lead author of a recent study on ‘The Great Darkness of Betelgeuse’. However, tens of thousands of years, even hundreds of thousands of years, are only astronomically ‘sooner or later’.
The more massive a star is, the exponentially shorter its lifetime. This is because the strong gravity speeds up nuclear fusion. Betelgeuse is about 20 times the mass of the sun, and although it is only 7.3 million years old, it is already showing signs of dying. Compared to the sun’s lifespan of about 10 billion years, it is literally an early death.
While the normal life of a star ends when it runs out of hydrogen and starts fusing helium in its core, its extended life as a red giant lasts beyond the helium burning phase. When the helium is exhausted, the star enters a period of burning carbon and oxygen, and finally fills the star’s core with iron. And in the next moment, it leads to fireworks, the biggest drama in the universe, a supernova explosion.
Betelgeuse boasts a size 730 times the diameter of the Sun, and if Betelgeuse were to be dragged to the place of our Sun, Mercury, Venus, Earth, and Mars would certainly be eaten away by Betelgeuse, and its surface would extend beyond the orbit of Jupiter.
If such a massive star causes a supernova explosion, its brightness will match the light emitted by the entire galaxy, and it is said that there will be no night on Earth for about 15 days. Will we be able to see the greatest drama of this universe while we are still alive? It has become a rite of passage for stargazers to check Betelgeuse first whenever they set their telescopes under the night sky.
Lee Kwang-sik, science columnist joand999@naver.com
