They photograph the first star outside our galaxy (and it’s not what you imagine)
A a huge star called WOH G64located in the Large Magellanic Cloud, one of the small galaxies orbiting the Milky Way. dies. This is an old familiar object, as astronomers have been observing it for decades. It is known, for example, that it has a size of approximately about 2000 times larger than our Sun, and which, by astronomical standards, dies its last death, since it has exhausted all its hydrogen.
At some point it will become supernovathis is the name given to the huge massive explosions with which some stars end their lives, phenomena of enormous force capable of throwing matter into space at a speed of 15,000 to 40,000 kilometers per second. But now we know what it looks like… and This is not what we expected.
A group of astronomers just received enlarged photo of WOH G64, which makes it the first image star located outside the Milky Way. The most curious thing about this case is that it was not captured by any space telescope – for example, Hubble or James Webb – but by an earthly telescope, although not any of them. This is the Very Large Telescope (VLT), the most powerful visible light observatory in the world, located in the Atacama Desert, Chile.
Researchers have long been interested in WOH G64. In 2005 and 2007, they used the VLT to study the star’s characteristics, which they continued to closely analyze for many years. However, they were unable to obtain a clear enough image to reveal its shape and structure.
An artist’s rendering of WOH G64, the first star outside our galaxy to be clearly imaged. The artist’s impression shows its main characteristics: an oval-shaped layer of dust and a ring, or toroid, around the star, the existence of which has been proven by new observations.
To achieve the desired image, the team had to wait for the development of a revolutionary invention called GRAVITY. second generation instrument capable of capturing images with exceptional sensitivity and precision through the use of interferometry, a technique that combines light from different telescopes, allowing astronomers to capture the finest details of faint objects.
Thus they managed to create the image is quite sharp combining data from each of the tools. However, when they revealed its appearance and shape, they discovered that This wasn’t exactly what they expected.
What is the reason for this strange oval shape?
One of the first surprises that astronomers received was strange oval shape surrounding the star. The image clearly shows an oval halo of light surrounding the star, surrounded by a wide ring. a shape inconsistent with previous observations of stars of this type. According to the researchers, there may be an explanation for this ovoid: materials released by the star, or perhaps the influence of an as-yet-undiscovered companion star, hypotheses that have not yet been demonstrated.
“We found that the star has undergone significant changes over the past 10 years, giving us a rare opportunity to witness the life of such a celestial body in real time,” says Gerd Weigelt, professor of astronomy at the Max Planck Institute. Institute of Radio Astronomy in Bonn (Germany) and co-author of the study.
Huge dying star
Red giants are huge stars with a relatively cold surface, although their diameter is usually tens and sometimes hundreds of times larger than that of our Sun. Their reddish appearance corresponds to their relatively low temperature, although their large diameter makes them glow much brighter.
The red giant WOH G64 is located in the Large Magellanic Cloud, a satellite galaxy of the Milky Way located 160,000 light-years away. This image shows the location of the star in the sky, as well as some of the VLTI satellite telescopes in the foreground.
This type of stars They were once main sequence suns. like ours, which fuses hydrogen at the core. However, at some point they ran out of fuel, so They began to burn helium, which they converted into heavier elements.
At these moments, huge The star expands, cooling its surface and becoming brighter. In their final stage before going supernova, they emit large amounts of gas and dust into space, and they do this irregularly and unstably, which can sometimes increase their brightness many times over.
But This is a deceptive shine. This is the glitter of death. In the case of the WOH G64, it is not yet known when and how it will be disabled. In the final stages of their lives, red supergiants such as WOH G64 shed their outer layers of gas and dust in a process that can take thousands of years, the study said.
This huge, cool red star is one of the most extreme of its kind, so any radical changes to its unstoppable extinction process could hasten its explosive end, explains co-author Jacco van Loon, director of the Kiel Observatory in the United Kingdom. who has been watching WOH G64 since a decadesince 1990.
Eons may pass, but The end is destined, as is the end of our Sun, which is estimated to die in about 5 billion years. But don’t worry, because by then there won’t be a trace of life left in this small corner of the galaxy.