New evidence that the nearby red giant Betelgeuse has a hidden companion

Another study revealed that for most of the last two thousand years the color of the star was yellow and not red, which shows that its transformation into a red giant is a new development, and therefore they distance the prediction of its transformation into a supernova

Betelgeuse, one of the brightest stars in the constellation Orion, is a red supergiant star that has attracted the attention of astronomers for many generations. This star, sometimes described as the "diva of the sky", continues to surprise researchers even in the present era. Two new studies indicate major changes the star has undergone, including a change in color and a disruption in its brightness cycle.

The "Great Blackout" of Betelgeuse

In late 2019, Betelgeuse surprised the astronomical community when it underwent a period of considerable dimming lasting several months, a period now called the "Great Dimension". After several months of observations, researchers explained the event by the fact that the star emitted a large plasma bubble that created dust that blocked some of the light reaching Earth. In addition, the surface of the star cooled, adding to the dimming seen from Earth.

But the disruption did not end there. Astrophysicist Andrea Dupree's team reported in August 2022 that the star's periodic brightness was completely disrupted after the event. In the past, the brightness of the star changed in a regular cycle of 400 days, when the star "breathed" - expanded and contracted alternately. However, after the Great Dimming, this cycle became irregular, and the star began to behave like "laundry in an unbalanced machine," according to Dupree.

This disruption may be caused by Betelgeuse's attempt to recover from the large plate of matter, which caused changes in the star's surface plasma. According to the researchers' calculations, the star ejected an amount of material equivalent to several times the mass of the Moon, creating a large cold spot that affected its brightness cycle.

The color change of Betelgeuse

The big blackout isn't the only interesting change that happened to Betelgeuse. Another study, conducted by a team led by Ralph Neuhäuser, revealed that the star has changed color over the past 2,000 years. While today Betelgeuse is a red star, historical records indicate that 2,000 years ago the star was yellow in color.

The color of a star is an indication of its developmental stage. Stars turn red when they reach the end of their lives, having consumed all their hydrogen and begun to expand and cool. Betelgeuse's relatively rapid change in color indicates that it reached its red supergiant stage very recently astronomically, while humanity was still alive to witness it.

What does the future hold for Betelgeuse?

Despite much excitement surrounding the changes Betelgeuse has experienced, its supernova explosion is unlikely to happen anytime soon. According to the researchers, if Betelgeuse became a red supergiant only in the last few years, it may take over a million years for it to explode and become a supernova.

Despite this, the star continues to be a fascinating object of study. Its changes in color and brightness teach us a lot about the way stars emit matter into space and the way the elements that make up planets and even living things like humans were formed. The researchers predict that in the future we will be able to observe clouds of dust ejected from Betelgeuse during the Great Dimming, which would confirm the theory of a large emission of material from a single event.

The two new studies on Betelgeuse show that this star, as always, continues to surprise and change our understanding of the processes that occur in stars close to the end of their lives.

More of the topic in Hayadan:

• 2012 - New craze: Betelgeuse will explode and this will apparently hurt the Earth
• Rare photo: The massive star Betelgeuse is on its way to collide with a wall of cosmic dust
• The famous star Betelgeuse has faded, but it still probably won't explode anytime soon