Located in the upper right of the constellation of Orion, Betelgeuse is a pulsating variable star that fluctuates periodically in brightness. Such Betelgeuse dimmed greatly in late 2019, and it was said that it might be a precursor to a supernova explosion. Currently, the brightness of Betelgeuse is coming back, and the researchers report that the note that the brightness of Betelgeuse fluctuates has changed.
Betelgeuse is one of only 21 first-magnitude stars and is the largest red supergiant in diameter among stars visible to the naked eye. If Betelgeuse is placed at the center of the solar system, its tip is said to be large enough to exceed the orbit of Jupiter.
In the star, synthesis by nuclear fusion is carried out from light elements to heavy elements, so nuclear fusion is performed first by hydrogen, then by helium nuclear fusion, and then by carbon or oxygen. Betelgeuse appears to be in the middle of helium fusion in the star’s core, and it is believed that it is likely to run out of fuel and explode in a supernova within 100,000 years.
In December 2019, it was reported that the brightness of Betelgeuse was about half that of October, recording the lowest ever observed, so it was said that it was a precursor to a supernova explosion. After that, it was reported that the brightness of Betelgeuse had returned.
In later studies, it was suggested that the large-scale dimming of Betelgeuse was due to the simultaneous occurrence of a temporary temperature drop and interstellar dust. According to this theory, when a cold spot forms on the surface of Betelgeuse, the area darkens, and at the same time, the dust formed on the spot gets stuck between the Earth and Betelgeuse, reducing the brightness of Betelgeuse seen from the Earth.
From 2022 to 2023, the brightness of Betelgeuse is gradually increasing, and in April 2023, the brightness of Betelgeuse reaches 156% of the normal value, and in May it is 142% brighter than usual. As a result, Betelgeuse, which was originally 10th in the sky, is now 7th in brightness.
A research team at the Harvard Smithsonian Center for Astrophysics published a research result that showed that the brightness fluctuation period changed after the Betelgeuse Great Dimming in a paper posted in the archive. Betelgeuse was originally a pulsating variable star whose bright and dark periods fluctuate every 400 days, but the current fluctuating period is said to be half of 200 days. This cycle is thought to fluctuate according to the internal expansion and contraction of Betelgeuse, and it is expected to return to the 400-day cycle in the next 5 to 10 years.
An astrophysicist said that one of the coolest things about Betelgeuse is that the final stages of the evolution of a large star can be seen almost in real time. Related information this placecan be found in
