Star outside our galaxy: First close-up image captured
Astronomers have achieved a groundbreaking milestone by capturing the first close-up image of a star outside our galaxy, the Milky Way. The star, named WOH G64, is located approximately 160,000 light-years away in the Large Magellanic Cloud, a small galaxy orbiting the Milky Way.
First zoomed-in picture of the extragalactic star | ESO News
Zooming into the star WOH G64
This significant achievement was made possible through the European Southern Observatory’s Very Large Telescope Interferometer (ESO’s VLTI), which provided the necessary resolution and sensitivity to observe the star in unprecedented detail.
Keiichi Ohnaka, an astrophysicist from Universidad Andrés Bello in Chile, said in an ESO press release, “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.”
The newly captured image reveals WOH G64 expelling gas and dust, signifying its final stages before it transforms into a supernova.
Image of the star WOH G64 taken by the VLTI
The observation of WOH G64, a red supergiant star roughly 2000 times the size of our Sun, has been a long-standing objective for Ohnaka’s team. The star’s enormous size and its location in the Large Magellanic Cloud have earned it the moniker “behemoth star.” Ohnaka and his colleagues have studied WOH G64 for years, utilizing ESO’s VLTI in Chile’s Atacama Desert to understand its characteristics better. However, an actual image of the star had remained elusive until now.
Location of the star WOH G64 in the Large Magellanic Cloud
The breakthrough came with the development of one of VLTI’s second-generation instruments, GRAVITY, which allowed the team to capture the light from four telescopes simultaneously. Comparing the new image with past observations, the team found that WOH G64 had dimmed over the last decade.
Ohnaka explained, “We discovered an egg-shaped cocoon closely surrounding the star. We are excited because this may be related to the drastic ejection of material from the dying star before a supernova explosion.”
This discovery provides a rare opportunity to observe the real-time evolution of a star in its final stages.
Gerd Weigelt, an astronomy professor at the Max Planck Institute for Radio Astronomy in Bonn, Germany, and a co-author of the study, added, “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.”
The egg-shaped cocoon surrounding WOH G64 has puzzled scientists, as it deviates from the shapes predicted by previous observations and models. The team hypothesizes that the unusual shape could be due to the star’s shedding process or the presence of an undetected companion star.
Looking ahead, the VLTI’s planned upgrades, such as the future GRAVITY+, promise to enhance the telescope’s capabilities, allowing astronomers to capture even fainter and more distant objects.
Ohnaka ended his statement by saying, “Similar follow-up observations with ESO instruments will be important for understanding what is going on in the star.”
ESO’s VLTI combines light from its Very Large Telescope’s 8-meter Unit Telescopes and smaller Auxiliary Telescopes, creating highly detailed images of the cosmos. This process, known as interferometry, essentially transforms the VLTI into a “virtual” telescope with the resolution equivalent to the maximum distance between its individual telescopes.
The European Southern Observatory (ESO) continues to push the boundaries of astronomical discovery, with facilities in Chile’s Atacama Desert offering unparalleled conditions for observing the sky. ESO’s commitment to international collaboration and state-of-the-art technology enables scientists worldwide to explore the universe’s secrets, furthering our understanding of cosmic phenomena.
Featured image is “Artist’s impression of the dying star WOH G64.”
“The image shows an artist’s reconstruction of the star WOH G64, the first star outside our galaxy to be imaged in close-up. It is located at a staggering distance of over 160 000 light-years away in the Large Magellanic Cloud. This artistic impression showcases its main features: an egg-shaped cocoon of dust surrounding the star and a ring or torus of dust. The existence and shape of the latter require more observations to be confirmed.
Credit: ESO/L. Calçada”
