Betelgeuse

An explosion is the most likely prospect of a red star and a major astronomical event, and therefore Betelgeuse is so interested in scientists. They got a rare opportunity to study the state of the supergiant before the explosion.

2021: The star is closer to Earth than previously thought

The simulation allowed scientists, led by specialists from the Australian National University, to revise the size of the star and the distance it is located from the Earth. It turns out that the supergiant is a little smaller and much closer to us than previously thought.

For a long time, scientists could not find out the real size of Betelgeuse - only assumptions were put forward. Previous studies have suggested that it is slightly larger in size than the orbit of Jupiter. In the course of the new work, it turned out that the star is smaller - it occupies only two-thirds of the size of the orbit of Jupiter, and also its radius is 750 times the radius of the Sun^[1].

With updated data on the physical size of Betelgeuse, the authors of the work were able to more accurately calculate the distance to it from the Earth. This is only 530 light years, which is 25% less than previous assumptions. However, the star is still too far away for its explosion, even if scientists are wrong and it will take place soon, to cause any damage to the Earth. No gamma-ray burst is expected from the explosion, and the X-ray and UV radiation from Betelgeuse cannot affect us in any way. Still, 530 light years is too far, and the explosion will be interesting only from an astronomical point of view.

2020: The star faded but another 100 thousand years may pass before the explosion

A supergiant star from the constellation Orion makes scientists nervous. Since the end of 2019, it has faded twice: at first, a decrease in brightness forced astronomers to expect an explosion, but by April 2020 the brightness to the star returned, albeit not for long. A few months later, Betelgeuse began to dim again, although not as much as the first time.

The first darkening, most likely, arose due to a cloud of dust emitted by a supergiant. The second episode, weaker, was studied by an international team of astronomers led by specialists from the Australian National University. Experts believe that this time pulsations became the cause of the star's sweating.

Shooting of the dimming of Betelgeuse due to a dust cloud in late 2019 - early 2020. Image: NASA, ESA, and E. Wheatley (STScI)

The researchers created a hydrodynamic model and modeled the seismic processes of the supergiant surface. Thanks to this, it was possible to find out that the darkening of the star visible from Earth causes ripples, which, in turn, are created by pressure waves.

Also, modeling helped calculate the phase of life in which the red star now resides. The result will not please those who hoped for celestial fireworks - helium is currently burning in the core of the supergiant, which means that the star is not planning to explode yet. Moreover, the Betelgeuse explosion can be expected for about another 100 thousand years.

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