Berlin – A star located 160,000 light years from Land was captured clearly for the first time thanks to the Extremely Large Telescope Interferometer (VLTI) located in the Atacama Desert, in Chilithe European Southern Observatory (ESO) reported this Thursday.
The observations reveal a star in the final stages of its life, expelling gas and dust before going supernova.
“For the first time, we have managed to take an enlarged image of a dying star in a galaxy outside our Milky Way,” said Keiichi Ohnaka, an astrophysicist at the Andrés Bello University of Chile, in the statement.
The new star observed, WOH G64, is located in the Large Magellanic Cloud, one of the small galaxies that orbit the Milky Way.
Astronomers have known about this star for decades and have appropriately named it “the giant star,” about 2,000 times the size of the Sun, which is why it is classified as a red supergiant star.
“We have discovered an egg-shaped cocoon that closely surrounds the star,” explained Ohnaka, lead author of a study that collects the observations and who noted that this “may be related to the drastic ejection of material from the dying star before “the explosion of a supernova.”
In 2005 and 2007, Ohnaka’s team used ESO’s VLTI, capable of capturing highly detailed images of the cosmos, located in the Chilean Atacama Desert, to learn more about the star’s characteristics.
They are currently continuing the study with one of the second generation instruments capable of capturing light from four telescopes, GRAVITY.
After comparing the new results with other previous observations of WOH G64, they were surprised to discover that the star had dimmed considerably in the last decade.
“This offers us a rare opportunity to witness the life of a star in real time,” added Gerd Weigelt, professor of astronomy at the Max Planck Institute for Radio Astronomy in Bonn, Germany, and co-author of the study.
Supergiants with unexpected shapes
The study shows that red supergiants, in their final stages of life, shed their outer layers of gas and dust in a process that can last thousands of years.
The group of astronomers considers that these detached materials may also be responsible for the dimming and unexpected shape of the dust cocoon that surrounds the star.
The new image, which shows that the cocoon is elongated, either by the detachment of the star or by the influence of a new star, surprised scientists, who expected a different shape based on previous observations and computer models.
“This star is one of the most extreme of its kind, and any drastic change could bring it closer to an explosive end,” said co-author Jacco van Loon, director of the Keele Observatory at Keele University in the United Kingdom, which has been observing WOH G64 from the 1990s.
As the star becomes dimmer, taking other close 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 soon, ESO said.
“Similar follow-up observations with the observatory’s instruments will be important to understand what is happening in the star,” Ohnaka concluded.