A team of astronomers led by Hideyuki Sayo (Tohoku University) has discovered that Betelgeuse is much larger than previously thought, more than 1,200 times wider than the Sun. This means the giant star may be running out of carbon fuel. “Once the carbon in the core is depleted, a core collapse is expected in a few decades, leading to a supernova explosion,” the authors write.
Betelgeuse, one of the most famous stars in the night sky, is in the constellation Orion and is a red supergiant. Its unusual behavior has attracted the attention of astronomers because it may herald a nearby supernova explosion.
Observations show that Betelgeuse periodically changes its brightness and size. This is due to pulsations that occur within the star. The pulsations cause changes in its volume and temperature, which is reflected in the brightness and color that we see from Earth.
The model created by Sayo and his colleagues simulates these pulsations and predicts how Betelgeuse’s brightness will change in the future. They claim that their model accurately matches observed data and provides a unique insight into the inner state of the star.
However, recent observations show that Betelgeuse has become significantly paler over the past month. This has caused concern among astronomers, as this dramatic change in brightness may be related to an upcoming supernova.
However, it is not yet possible to say for sure whether this is a precursor to a supernova or just a temporary change. Astronomers continue to study Betelgeuse and hope to get more data to better understand what is going on inside this mysterious star.
Betelgeuse, one of the brightest and most recognizable stars in the night sky, has long attracted astronomers’ attention for its rapid changes. It was described by Ptolemy as an orange-brown star, while Chinese observers saw it as yellow. Recently, astronomers have classified Betelgeuse as a red giant near the end of its life. This means that the star should explode as a supernova in the next hundreds of thousands or millions of years. Betelgeuse has also been found to pulsate, becoming brighter and dimmer over periods ranging from a few months to several years.
In 2019, there was an unexpected fading of Betelgeuse, causing concern among astronomers. They wondered if the star was approaching its supernova. However, further observations showed that the clouding was caused by a dust cloud and that the Betelgeuse supernova was still a considerable distance away.
Now scientists from Tohuko University in Japan offer a new hypothesis. They have re-analyzed the data and concluded that Betelgeuse may be closer to its supernova than previously thought. They argue that the star is in the late stage of burning carbon in its core and could be the next galactic supernova.
To understand this hypothesis, it is necessary to know how stars change over the course of their lives. Stars form from gas, mostly hydrogen and helium. When these gas clouds collapse, hydrogen nuclei merge, releasing huge amounts of energy. This energy heats the star and prevents it from collapsing further. Over time, however, the hydrogen fuel is exhausted, and the star begins to burn heavier elements, such as carbon. This causes the star to expand, turning red, and eventually going supernova.
Betelgeuse is already in a late stage of carbon burning, indicating that it may be closer to its supernova than previously thought. The pulsations of the star also play an important role in this hypothesis. The pulsations cause a temporary increase in the brightness of the star, and then its dimness. Measurements of these pulsations allow scientists to infer the star’s mass and the fusion processes occurring in its core.
If the hypothesis turns out to be correct, Betelgeuse could become the next galactic supernova. This event will be observed from Earth and will provide astronomers with a unique opportunity to study the processes occurring during supernovae in nearby galaxies.