This star was Yellow 2000 years ago and now, it is a fearsome RED and fated to explode
Red supergiant star Betelgeuse was not always this way. It used to be a blue-white O-type star.
The red supergiant star Betelgeuse is on the brink of death. A slow and painful death. But it was not always this way. Initially, the star used to be a blue-white O-type star, the most massive stellar weight class, fusing hydrogen. And as it is moving towards the end of its life, it has turned into a more red and golden hue. Astronomers have recently figured out how the star looked around 2000 years ago. According to a review of observations of the star dating back to ancient past, it would have been yellow in hue around 2,000 years ago. As reported by Phys.org, “As nuclear fusion in the centre of a star progresses, brightness, size, and colour also change.”
Astrophysicists of Friedrich Schiller University Jena, Germany, along with their colleagues of other subjects from the U.S. and Italy, have traced the colour change in the bright star. The study has been published in the current issue of Monthly Notices of the Royal Astronomical Society.
Astronomer Ralph Neuhauser from Jena has mentioned the historical transmissions about Betelgeuse suggest "The very fact that it changed in colour within two millennia from yellow-orange to red tells us, together with theoretical calculations, that it has 14 times the mass of our sun—and the mass is the main parameter defining the evolution of stars." Neuhauser further said that the Betelgeuse is now 14 million years old and is in its late evolutionary phases and in about 1.5 million years, it will finally explode as a supernova. Betelgeuse has aged qute rapidly, faster than smaller stars, simply because of its astronomical size.
He also shared that a statement by the Danish astronomer Tycho Brahe, who died in 1601, had concluded that Betelgeuse was more red than Aldebaran in the 16th century and today it is closer in hue to Antares – a star whose name means 'like Mars'. This gave researchers a parameter to estimate Betelgeuse's current age, and how long it will survive.