A star 160,000 light-years from Earth has become the epic subject of the first close-up portrait of a star in another galaxy. is called WOH G64A red supergiant star in the Large Magellanic Cloud dwarf galaxy orbiting the Milky Way. It is so large that for several years it was called the “Beast” or “Behemoth” because its radius is almost 2000 times that of the Sun.

This enormous size made it a perfect target for a portrait using the Very Large Interferometer Telescope at the European Southern Observatory. It’s big enough that we can zoom in and see details we’ve never seen before.

“We discovered an egg-shaped coconut near the star,” says astrophysicist Keiichi Onaka of Universidad Nacional Andres Bello in Chile. “We’re excited because it could be due to a sudden ejection of material from a dying star before a supernova explosion.”

It is quite difficult to describe the stars inside the Milky Way right here. The red giant star Betelgeuse is a perfect example; Although the object’s radius is 764 times the radius of the Sun and its distance is less than 650 light-years, our images of the object are so blurry that astronomers are still trying to understand why its light fluctuates so wildly.

WOH G64 is about three times the size of Betelgeuse, but 250 times the distance. Therefore, Earth appears much smaller and dimmer than Betelgeuse, one of the brightest stars in the sky. Onaka and his colleagues have been working on Behemoth for years, but they had to wait for the technology to be powerful enough to create a detailed portrait.

This technology takes the form of a device called GRAVITY, designed to observe very small, very faint objects. Considering how far behind the WOH G64 is, it definitely falls into the small and flimsy category. The researchers conducted their observations in December 2020 and then had to go through the arduous work of cleaning, processing and reconstructing the data to solve the set target. So, although the image may appear blurry, the level of detail the researchers managed to achieve is truly incredible.

Observations made in 2005 and 2007 showed that WOH G64 was surrounded by dusty material. It’s exciting that the star is in the red supergiant stage. This is the end of the life of massive stars, initially around 8 to 35 solar masses. When the nuclear fuel required for fusion in a star’s core runs out, it becomes unstable, burns very hot, and swells to enormous sizes before exploding as a supernova.

The powder material showed that WOH G64 was in an extremely unstable stage of its life, experiencing strong mass loss as it grew towards the end. Now new observations have shown that the star is actually getting dimmer.

“We found that the star has undergone significant changes over the last 10 years, giving us a rare opportunity to observe the life of the star in real time,” says astronomer Gerd Weigelt of the Max Planck Institute for Radio Astronomy in Germany.

Researchers believe that the star’s dimming may be the result of its mass loss. The gas and dust it sneezes out blocks some of its light from reaching us, causing the star to appear dimmer to our telescopes. What surprised the scientists was the oval, egg-like shape of the emission bubble. Their simulations, based on previous observations, suggested that the shape should be different. It’s not clear why it has this shape, but there may be several explanations.

This may be related to the way the material is published; the way the star moves in the space around it; or even the existence of an as-yet-unseen binary companion that somehow shapes outputs that scientists have not yet identified. Behemoth represents very uncharted and exciting territory. The mass loss phase of a red supergiant lasts several thousand years; Which means the star is truly on the brink. This could tell us how big stars end their lives in a way we’ve never seen before.

“This is one of the most extreme of its type of star,” says British observatory director and astronomer Kiel Jakko van Loon, “and any sudden change could bring it closer to an explosive end.” The study was published on: Astronomy and Astrophysics.