Scientists have finally discovered the reason why Betelgeuse – one of the brightest stars in the sky, mysteriously dimmed in 2019.
The dimming and brightening process of Betelgeuse. (Photo: ESO)
When Betelgeuse – a star 1,000 times larger than the Sun, located about 725 light-years from Earth, began to dim in early 2019, scientists believed it was a sign that one of the brightest stars in the night sky was dying, losing energy. This process leads to a massive supernova explosion.
However, Betelgeuse has now returned to its normal brightness.
A study published in the journal Nature on June 16 reveals that Betelgeuse dimmed due to a layer of dust surrounding it.
According to the research team, Betelgeuse emitted a large gas bubble. As its surface cooled down, this temperature drop was sufficient for heavier-than-air elements, such as silicon, to condense into a layer of dust around it. This dust cloud persisted for several months, blocking the light from Betelgeuse and causing it to appear increasingly dim.
“We directly witnessed the formation of what is called stardust,” said astrophysicist Miguel Montargès, the lead author of the study.
Although Betelgeuse did not become a supernova, its dimming provides important insights into the universe.
