- Jonathan Amos
- BBC science reporter
Astronomers finally claim to have solved the mystery why one of the most famous and brightest stars in our sky suddenly began to dim just over a year ago.
Betelgeuse, a red giant star in the constellation Orion, suddenly darkened in late 2019 and early 2020.
This behavior has generated speculation that It could be about to explode.
However, a team of scientists using the Very Large Telescope (VLT) in Chile said that the cause is most likely due to a huge cloud of dust passing between the star and us.
Even if you cannot name many places in the sky, you will certainly be able to recognize Betelgeuse with the naked eye.
Is it Orange dot in the upper right corner of Orion (The Hunter), or in the lower right corner if you are watching from the southern hemisphere.
Betelgeuse is relatively close to Earth, about 550 light-years away, and is known as the quasi-regular variable star. It naturally brightens and darkens over about 400 days.
But what happened a year and a half ago was out of the ordinary. The loss of luster was much greater than had ever been recorded.
Astronomer Miguel Montargues and colleagues investigated the event by VLT from the European Southern Observatory (SEO).
it’s a One of the most powerful telescopes on Earth, which is located in the Atacama Desert, Chile and has enough resolution to produce a direct image of Betelgeuse.
The researchers compared images of before, during, and after dark and expected models to see what kind of behavior could lead to the observations obtained.
There were two ideas that prevailed. Maybe it was A large cold region on the surface of the star, because giant red giants such as Betelgeuse are known to have large load cells that can generate hot spots and cold spots.
On the other hand, there may have been a file smother Which was forming in front of the star from our perspective on Earth.
The explanation turns out to be “a bit of both,” says Emily Cannon, an astrophysicist at KU (A Catholic University) in Leuven, Belgium.
He explained to BBC News: “Our general idea is that there is a cold region in the star, which, due to the local decrease in temperature, caused the gas emission to condense earlier and turn into dust.”
“So, the cold region on the surface will make us see the star less bright. But later, this condensation of dust will increase the rapid loss of brightness of the star.”
Betelgeuse Mass between 15 and 20 times the mass of the Sun. It is possible that an object of this size will transform into a supernova at some point.
So it wasn’t unreasonable to consider that when the unusual dimming occurs, Betelgeuse can be dizzyingly close to exploding.
“I don’t think this event means Betelgeuse will go supernova anytime soon, although that would be incredibly interesting and I was almost looking forward to it!” Emily Cannon admitted.
“We know that giant red giants can show an increased rate of mass loss, which may be an indication that there is a later stage in their lives at which they can become supernovae. But we think Betelgeuse is a relatively small red giant and probably has a lot left over. time”.
And how long is that? Dozens, maybe hundreds or thousands of years is the time astronomers often cite.
It would be something absolutely amazing; The event will be visible in broad daylight.
The last supernova can be observed in Milky WayAnd the our galaxyAnd the The star was Kepler, observed in 1604. Astronomers’ records at the time indicate that it was visible during the day for more than three weeks.
The report of the investigation team of Miguel Montargues was published in the specialized journal nature.
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