Betelgeuse is an ageing, red supergiant star 645 light-years away from earth, that has swelled in size due to complex, evolving changes in its nuclear fusion furnace at the core. The star is so huge now that if it is replaced by the Sun at the center of our solar system, its outer surface would extend past the orbit of Jupiter. Betelgeuse is a variable star that expands and contracts, brightening and dimming, on a 420-day cycle. Massive supergiant stars like Betelgeuse are important because they expel heavy elements such as carbon into space that become the building blocks of the new generation of stars. Carbon is also a basic ingredient for life as we know it. Hubble researchers suggest that the dust cloud formed when super-hot plasma unleashed from an upwelling of a large convection cell on the star’s surface passed through the hot atmosphere to the colder outer layers, where it gets cooled and forms dust grains. The resulting dust cloud blocks light from about a quarter of the star’s surface, beginning in late 2019.
By April 2020, the star returned to normal brightness. Recent outburst was reported to be two to four times more luminous than the star’s normal brightness and then, about a month later, the south part of Betelgeuse dimmed conspicuously as the star grew fainter. Scientists think that a dark cloud resulted from the outflow and they estimated that about two times the normal amount of material from the southern hemisphere was lost over the three months of the outburst. Betelgeuse, like all the other stars, is losing mass all the time, in this case at a rate of 30 million times higher than the Sun. Betelgeuse is at the end of its life cycle and will die out with a cosmic explosion called a supernova. Betelgeuse is unlikely that it will happen soon as these outbursts are common before the supernova phase and lasts up to million years.
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