Something Strange Is Happening to This Giant Star. It Just Activated Self-Destruction

Astronomers are witnessing an extremely rare and accelerated cosmic spectacle – the final moments in the life of one of the largest known stars, WOH G64. The object located in the neighboring galaxy of the Large Magellanic Cloud is undergoing a dramatic evolutionary transformation from the red supergiant phase to the yellow hypergiant stage. The key is the speed of this change – a process that, according to standard stellar evolution models, should take thousands of years is unfolding here in just a few years. Observations, particularly clear since around 2014, show the star rapidly heating up and violently ejecting its outer layers into space. A team of scientists led by Gonzalo Muñoz-Sanchez from the National Observatory of Athens presented the research results in the prestigious journal "Nature Astronomy." According to the researchers, the observed transformation is a clear signal that the massive star is preparing for the final act of its existence. For an object with the parameters of WOH G64, this most likely means the explosion of a supernova on an unimaginable energy scale. However, an alternative scenario cannot be ruled out, in which the star collapses without a spectacular explosion, directly forming a black hole. Regardless of the finale, this event will take place in our cosmic neighborhood. Studying the final stages of massive stars' lives is a cornerstone of modern astrophysics. Theory predicts that stars significantly more massive than the Sun end their lives in spectacular supernova explosions, which scatter heavy elements essential for planet and life formation throughout the cosmos. However, direct observations of these processes are extremely rare due to their cosmic timescale. WOH G64 thus provides a unique opportunity to verify theoretical models. The phenomenon is all the more valuable because it concerns a star with nearly record-breaking parameters. Its radius, exceeding 1500 solar radii, makes it one of the largest known celestial bodies. Paradoxically, this cosmic colossus is, from an evolutionary perspective, an infant – it is estimated to have ignited only about five million years ago. For comparison, the Sun has existed for about 4.6 billion years and is only halfway through its life. Observations of WOH G64 are being conducted by a network of telescopes worldwide, allowing for continuous monitoring of its state. The coming months and years may bring decisive moments in its evolution, offering astronomers an unprecedented insight into the mechanisms governing the death of the largest stars. „„It's like watching a slow-motion countdown to an explosion. Changes we usually think of as static over millennia are happening right before our eyes.”” (This event does not pose a direct threat to Earth, but its observation will be of fundamental importance for science. A supernova explosion in our galactic neighborhood would be visible to the naked eye in the sky for many months, even years, becoming one of the brightest points in the night sky.) — Gonzalo Muñoz-Sanchez This event does not pose a direct threat to Earth, but its observation will be of fundamental importance for science. A supernova explosion in our galactic neighborhood would be visible to the naked eye in the sky for many months, even years, becoming one of the brightest points in the night sky.