For the first time, astronomers have captured an enlarged image of a star in a neighboring galaxy, specifically WOH G64, a red supergiant located approximately 160,000 light-years from Earth in the Large Magellanic Cloud.
This achievement, combining scientific precision and cutting-edge technology, provides unprecedented insights into the final moments of a massive star before it collapses into a supernova explosion.
The research team utilized the Very Large Telescope (VLT) at the European Southern Observatory (ESO) in the Atacama Desert, Chile. The GRAVITY instrument, designed to capture light from distant objects with high sensitivity, enabled detailed observations of WOH G64's environment.
“For the first time, we have succeeded in taking an enlarged image of a dying star in a galaxy outside our own Milky Way,” stated Keiichi Ohnaka, an astrophysicist from Andrés Bello University in Chile and lead author of the study published in Astronomy & Astrophysics.
WOH G64 is regarded as one of the most extraordinary stars observed to date, with an estimated size up to 2,000 times that of the Sun. Its unique characteristics, including an egg-shaped envelope of gas and dust, have intrigued scientists for decades.
The nebula formed by stellar material ejection indicates that WOH G64 is in the final stages of its existence. Originally, the star had a mass between 25 and 40 times that of the Sun but has lost much of its mass over time, leading to a state of instability before its final collapse.
Throughout its life, estimated to be between 10 and 20 million years, WOH G64 has undergone drastic changes. Recently, astronomers observed that the star is dimming, attributed to the accumulation of stellar material in its outer envelope. This unusual behavior suggests it may be nearing a supernova explosion, one of the most energetic events in the universe.
The photographic capture of WOH G64 was made possible through advanced technologies at the European Southern Observatory. The GRAVITY instrument combines light from four telescopes to create detailed images of extremely distant and faint objects.
Initial observations of the star date back to 2005 and 2007, when astronomers began studying its surroundings with the VLT. However, it was not until the development of GRAVITY that an enlarged image of WOH G64 was obtained, allowing researchers to observe the structure of its gas and dust cocoon, providing insights into its evolutionary process.
The distance of 160,000 light-years means that the light we currently see from WOH G64 left the star thousands of years ago. Despite this challenge, the clarity of the image surpasses any previous record of a star in another galaxy, marking a milestone in astronomy.
The first detailed image of a star beyond the Milky Way represents a significant advancement for science. It not only aids in understanding the final stages of red supergiants but also offers a unique opportunity to study how galactic conditions influence stellar evolution.
The Large Magellanic Cloud, where WOH G64 resides, has a chemical composition distinct from that of our galaxy, with a higher presence of hydrogen and helium but fewer metallic elements. These differences may affect how stars are born, evolve, and die, making this discovery a valuable source of information about the early universe.
Additionally, studying WOH G64 could shed light on phenomena such as nebula formation and supernova explosions, events that play a fundamental role in creating heavy elements essential for life.
Keiichi Ohnaka noted that this image not only documents a crucial moment in a star's life but also underscores the potential for future research with instruments like GRAVITY+. Technological advancements will enable further exploration of stars in neighboring galaxies, expanding our knowledge of the cosmos. For now, WOH G64 remains a subject of ongoing study.