Evrim Yazgin
Cosmos science journalist
Astronomers have taken stargazing to all new extremes by taking the first close up image of a star in another galaxy and it might be on the verge of going supernova.
“For the first time, we have succeeded in taking a zoomed-in image of a dying star in a galaxy outside our own Milky Way,” says Keiichi Ohnaka, an astrophysicist from Universidad Andrés Bello in Chile.
The star, WOH G64, is in the Large Magellanic Cloud – a small galaxy that orbits the Milky Way – about 160,000 light-years from Earth. WOH G64 is a red supergiant about 2,000 times larger than our Sun.
The Large Magellanic Cloud has also recently provided the first evidence of a planet-forming disc around a star in another galaxy.
Using the European Southern Obervatory’s (ESO) Very Large Telescope Interferometer (VLTI), in the Atacama Desert in northern Chile, the team achieved unprecedented sharpness of an image of objects in another galaxy.
Such clarity revealed interesting features which are published in the journal Astronomy & Astrophysics.
“We discovered an egg-shaped cocoon closely surrounding the star,” lead author Ohnaka says. “We are excited because this may be related to the drastic ejection of material from the dying star before a supernova explosion.”
Even within our own galaxy, only about 25 zoomed in pictures of stars have been taken to date.
Creating an image WOH G64 required the completion of one of VLTI’s second-generation instruments called GRAVITY – an interferometer that combines the light of all 4 VLT telescopes in the Atacama to produce high-sensitivity pictures.
It has provided astronomers an opportunity to watch how the distant star has changed over time.
“We have found that the star has been experiencing a significant change in the last 10 years, providing us with a rare opportunity to witness a star’s life in real time,” says co-author Gerd Weigelt, an astronomy professor at the Max Planck Institute for Radio Astronomy in Bonn, Germany
“This star is one of the most extreme of its kind, and any drastic change may bring it closer to an explosive end,” adds co-author Jacco van Loon from the UK’s Keele Observatory Director, UK, who has been analysing data from WOH G64 since the 1990s.
