First enlarged image of a star outside our galaxy

Nov 21. () –

The VLT telescope of the European Southern Observatory (ESO) in Chile has made it possible to take the first close up image of a star in a galaxy outside our own Milky Way.

Located at the impressive distance of 160,000 light years Of us, the star WOH G64 was photographed thanks to the sharpness offered by the Very Large Telescope Interferometer (VLTI). New observations reveal dying star spewing gas and dust, in the last stages before becoming a supernova.

“We discovered an egg-shaped envelope that closely surrounds the star,” he says. in a statement Keiichi Ohnaka, astrophysicist at the Universidad Andrés Bello, in Chile, and lead author of the research, published in the journal Astronomy & Astrophysics. “We are excited because this may be related to the dramatic ejection of material from the dying star before a supernova explosion.”

While the astronomical community has obtained about two dozen magnified images of stars in our galaxy, revealing their properties, there are many other stars that inhabit other galaxies, so far away that observing even one of them in detail is extremely challenging. Until now.

A RED SUPERGIANT 2,000 TIMES THE SIZE OF THE SUN

The newly photographed star, WOH G64, is located within the Large Magellanic Cloudone of the small galaxies that orbit the Milky Way. The astronomical community has known about this star for decades and has dubbed it the “giant star.” Approximately 2,000 times the size of our Sun, WOH G64 is classified as a red supergiant.

Ohnaka’s team had long been interested in this giant star. In 2005 and 2007, they used ESO’s VLTI, located in Chile’s Atacama Desert, to learn more about the star’s characteristics, and continued to study it in subsequent years. But getting a real image of the star remained elusive.

To obtain the desired image, the team had to wait for the development of one of the VLT’s second-generation instruments, GRAVITY. After comparing their new results with other previous observations of WOH G64, They were surprised to discover that the star had become dimmer over the past decade.

“We have discovered that the star has undergone a significant change in the last 10 years, giving us a unique opportunity to witness the life of a star in real time,” says Gerd Weigelt, professor of astronomy at the Max Planck Institute for Radio Astronomy. in Bonn (Germany) and co-author of the study. In its final stages of life, Red supergiants like WOH G64 shed their outer layers of gas and dust in a process that can last thousands of years.. “This star is one of the most extreme of its kind, and any drastic change could bring it closer to an explosive end,” adds co-author Jacco van Loon, director of the Keele Observatory at Keele University, UK, who has been observing WOH. G64 since the 1990s.

The team believes that these materials ejected by the star may also be responsible for the dimming and unexpected shape of the dust envelope surrounding the star. The new image shows that the envelope is stretched, which surprised the scientific community, which expected a different shape based on previous observations and computer models. The team believes that egg shape wrapper It could be explained by the loss of material from the star or by the influence of an as yet undiscovered companion star.

As the star becomes fainter, obtaining more close-up images of it becomes increasingly difficult, even for the VLTI. However, planned upgrades to the telescope’s instrumentation, such as the future GRAVITY+, promise to change this before long. “To understand what is happening in the star, Similar follow-up observations with ESO instruments will be essential“concludes Ohnaka.