Astronomers have managed to capture images of the giant star Betelgeuse, showing that one of the brightest stars in the Milky Way has lost much of its brightness in recent months, according to a statement by the European Southern Observatory (ESO). ) published this Friday.
The images, taken thanks to ESO’s Very Large Telescope, a set of four large telescopes, make it possible to visualize the surface of this “red supergiant” located in the constellation of Orion, showing its fading, as well as an apparent change of its shape.
The star was among the 10 brightest in the galaxy, but since mid-November 2019, its luminosity has dropped drastically, which has put astronomers in turmoil and launched a vast observation campaign. The images revealed this Friday were made possible by the SPHERE instrument, installed on ESO’s Very Large Telescope (VLT) in Chile.
“We can clearly see that the star’s brightness has dropped on half of its apparent surface,” said Miguel Montargès, astrophysicist at KU Leuven University, in Belgium. “It seems from these images that the brightness is still decreasing, but less quickly,” he added.
A risk of supernova?
The sudden fading of the giant star boiled astronomers. Several hypotheses are put forward: it could be an ejection of gas forming dust and hiding the radiation or the agony of Betelgeuse.
This last scenario would result in a supernova explosion. If it seems unlikely in the near future, it makes astronomers dream: the star at the end of its life having no more “fuel” (from nuclear fusion), its heart would collapse on itself and would form a neutron star, a very compact object that creates a shock wave completely dislocating the star, all in just a few hours.
But “a priori, what we see on the images does not seem to be linked to a possible explosion”, according to Eric Lagadec (Observatory of the Côte d’Azur). According to him, the change in the shape of the star is linked either to “cooling or to dust that has formed near the star”.