European astronomers have received the first detailed photographs of the surface of the star Betelgeuse, whose brightness unexpectedly dropped by 63% at the end of last year. Their study made scientists doubt the imminent death of this star, writes the press service of the European Southern Observatory (ESO).
“We have two explanations for what caused this tarnishing and changed the shape of the star. On the one hand, this could be due to the cooling of the surface of Betelgeuse as a result of unusually powerful bursts of activity in its interior, and on the other, as a result of the release of large amounts of dust that prevents its light from reaching the Earth ", - Miguel Montarges, an astronomer from the Catholic University of Leuven (Belgium), commented on the work.
Betelgeuse is one of the largest and brightest stars in the sky, located in the constellation Orion. The star can be easily seen with the naked eye due to the fact that it is located at a short distance from the Earth, as well as due to its enormous size and mass, which is 15-25 times greater than the sun. For comparison, if Betelgeuse were in the center of the solar system, its outer layers would reach approximately the same regions where the orbits of Mars or Jupiter now lie.
According to the current estimates of astronomers, Betelgeuse is now in the last stage of stellar evolution, the stage of a red supergiant. This is how scientists call old stars, which have almost completely exhausted their hydrogen reserves, expanded dramatically and began to dump the material of their outer shells into open space. This process leads to the creation of huge amounts of dust and the formation of bright gas and dust nebulae.
Stellar eclipse
Some features in Betelgeuse's brightness fluctuations indicate that this star will end its existence in the next few thousand years. It can turn into a supernova, the outburst of which will be clearly visible to observers on Earth even during the day. This generates great interest in the fate of the dying space giant from both astronomers and ordinary people.
At the end of December last year, scientists began to notice that Betelgeuse was beginning to fade rapidly. By the beginning of January, the strength of its luminescence had decreased by about 63%, reaching record low values for the last 25 years of observations. Its tarnishing further spurred the interest of astronomers, who began to closely follow the star.
New photographs of the surface of Betelgeuse, which the VLT took in late January, made scientists doubt that this star is close to death. The fact is that in these photographs, astronomers saw traces of a giant cloud of dust, which the star released in approximately the same direction in which the Earth and the Sun are located.
'An animation that shows how the brightness of Betelgeuse changed from January to December 2019. Credit - ESO / M. Montargès et al '
This comparison photo shows the view of Betelgeuse before and after the unprecedented reduction in its luster. Observations were made with the SPHERE receiver at the VLT telescope (ESO) in January and December 2019