Astronomers have discovered one of the largest stars in the universe undergoing a rapid transformation from a red supergiant to a hotter yellow hypergiant. The star, WOH G64, underwent significant changes in just a few years, defying the expected course of stellar evolution.
Researchers analyzed data from the Optical Gravitational Lensing Experiment (OGLE) and found that the star’s surface temperature increased by 1,000 K, its pulsation pattern disappeared, and it shifted to a warmer color. The team concluded that WOH G64 has transformed into a yellow hypergiant, a rare late stage of stellar evolution.
The study reveals that massive stars can change direction rapidly, rather than following a predictable path to explosion. The star’s transformation is also linked to its hidden companion, a hotter blue star that is likely part of a symbiotic system. The two stars are locked in a gravitational partnership, with one altering the other’s surroundings and appearance.
The discovery sheds light on the mysterious behavior of massive stars and highlights the importance of long-term sky watching. By studying rare events like WOH G64, astronomers can catch stellar evolution as an ongoing process rather than a one-time record. The study provides valuable insights into the complexities of stellar evolution and the role of hidden companions in shaping the final stages of massive star life.
Source: https://www.earth.com/news/one-of-the-largest-stars-in-the-universe-suddenly-changed-color