If the star Betelgeuse currently appears red to the naked eye, this has not always been the case. Researchers have just shown that its transformation into a red supergiant happened very recently and that it was still a yellow star 2,000 years ago!
During its evolution, when theit has used up all of its fuel and can no longer carry out nuclear fusion, so it moves on to the next stage that depends on it initial. L analyzed in a study in the journal , is no exception. It is currently in the stage of that is, it is removed from the main sequence and will become a in a very short time on an astronomical scale.
While she has already surprised during histhe second brightest star of the it interested researchers for something else: its color. If it currently appears red, the team has just shown that it wasn’t always like this! This is demonstrated by the ancient texts, ranging from three millennia ago to today “Betelgeuse rapidly evolved in color as it crossed the “explains the study, namely that it was still yellow 2,000 years ago!
This type of evolution is rarely observable on a human scale.
Either in the writings of the Chinese court Sima Qian in 100 BC J.-C., or in the accounts of “Mediterranean Antiquity (Igino,Germanicus, Manilius and Cleomedes) “, is described 2,000 years ago as similar in color to or simply yellow. “From these clarifications it can be concluded that Betelgeuse at that time was colored between the white-blue of Sirius and Bellatrix and the red of Antares”explains Ralph Neuhäuser in a first author of the study and professor at the University of Jena.
A fact that may seem insignificant but which is important. “The very fact that it has changed color in two millennia from yellow-orange to red tells us, with theoretical calculations, that it has 14 times the mass of our– and mass is the main parameter that defines the evolution of starsexplains R.Neuhäuser. Betelgeuse is now 14 million years old and in its final stages of evolution. In about 1.5 million years, it will finally explode as a supernova ”.