The European Southern Observatory (ESO) described the disappearance of a massive unstable star located 75 million light years from Earth as a “cosmic mystery”.
Studies carried out between 2001 and 2011 had determined that the celestial body was in a late stage of its evolution.
Astronomer Andrew Allan wanted to know how these types of stars end their lives, so in 2019 he again pointed the Very Large Telescope (VLT) towards the dwarf galaxy Kinman.
However, the team that also comprised experts from Ireland, Chile and the United States found no traces of the star.
“Instead, we were surprised to discover that the star had disappeared!” Explained the also PhD student at Trinity College Dublin.
The group first used the Espresso instrument in August 2019, which groups the VLT’s four eight-meter telescopes. However, it was impossible to find the signs that previously pointed to the presence of the star. Months later, the scientists tested the X-shooter instrument, but there were no results either.
Located in the constellation Aquarius, the Kinman dwarf galaxy is too far away for astronomers to see its individual stars, but they can detect traces of some of them, ESO explained in a statement.
“From 2001 to 2011, light from the galaxy showed constant evidence that it hosted a ‘blue light variable’ star some 2.5 million times brighter than the Sun. Stars of this type are unstable and show occasional radical changes in their spectra and brightness. Even with those changes, they leave specific traces that scientists can identify, “he added.
“It would be very unusual for such a massive star to disappear without producing a brilliant supernova explosion,” added the study’s lead author, whose results were published in the Monthly Notices of the Royal Astronomical Society.
“If true, it would be the first direct detection of such a monstrous star that ends its life this way,” said Allan.
In this regard, his colleague José Groh said that “it is possible that we have detected the death of one of the most massive stars in the local universe.”
Data obtained in the past decade indicated that “the star of the dwarf galaxy Kinman may have been experiencing a strong period of outbursts that probably ended sometime after 2011.”
“Blue luminous variable stars of this type are prone to experiencing gigantic bursts throughout their lives, causing the rate of mass loss of stars to increase and increasing their luminosity dramatically,” ESO said.
“Astronomers have suggested two explanations for the star’s disappearance and the lack of a supernova. The outburst could have resulted in the blue luminous variable transforming into a less luminous star, which could also be partially hidden by dust, “said the organism.
The second option is that “the star may have collapsed into a black hole without producing a supernova explosion. This would be an unusual event, as our current understanding of how massive stars die suggests that most end their lives by exploding as supernovae. ”
Editor’s recommendations
–
