The astronomers of Very Large Telescope Interferometer (VLTI)managed by the European Southern Observatory (ESO), have obtained an unprecedented result: the first close-up image of a dying star located outside our Milky Way. The protagonist of this discovery is WOH G64a red supergiant wrapped in an unusual egg-shaped cocoon of gas and dust.
This star, which is located in the Large Magellanic Clouda satellite galaxy 160,000 light-years away, is a behemoth that surpasses the Sun by more than 2,000 times. Known as “the giant star”, it has been the subject of studies for decades, but never before have researchers been able to observe its structure and peculiar environment so closely.
An egg-shaped cocoon: the surprising discovery
Second Keiichi Ohnakaastrophysicist and research leader, this image represents a fundamental turning point:
“For the first time we have managed to capture a detailed image of a dying star located in a galaxy other than ours.”
WOH G64, belonging to the category of red supergiantsis a star in the final phase of its life, in which the outer layers are expelled to form envelopes of gas and dust. However, what amazed scientists was the shape of its cocoon: instead of being spherical, it appeared elongated, resembling the shape of an egg.
Ohnaka explained that this peculiarity could be linked to massive expulsions of material that precede the star’s transformation into a supernova.
“This discovery excites us, because it allows us to observe in real time the dramatic process that occurs before the final explosion of a star.”
The importance of WOH G64 for modern astronomy
For scientists like Gerd Weigelt from the Max Planck Institute for Radio Astronomy, WOH G64 represents an extraordinary opportunity to study the death of a star. Its recent luminous dimming, recorded in the last decade, has been attributed to the thickening of the layers of dust and gas expelled by the star itself.
Jacco van Loondirector of the Keele Observatory, underlined the importance of the phenomenon:
“It is one of the most extreme stars known, and any drastic change could bring it closer to the inevitable final explosion.”
Scientists also hypothesize the presence of a companion star that could influence the gas dynamics around WOH G64. Thanks to advanced tools like GRAVITY+which will soon be implemented in the VLTI, it will be possible to follow the final phases of this star more closely.
A new frontier for star observation
The extraordinary precision of the VLTI, which combines light from four telescopes to obtain images of very distant objects, marks a step forward in understanding the life cycles of stars. WOH G64 is the first star outside the Milky Way to be captured with such clarity, but it certainly won’t be the last.
As Ohnaka stated:
“Follow-up observations with ESO instruments will be key to deepening our understanding of these phenomena.”
The discoveries related to WOH G64 open new perspectives for the study of stars in distant galaxies, shedding light on how the universe works.
