NEW DELHI: In a groundbreaking discovery, ISRO’s AstroSat has captured a never-before-seen nuclear explosion in the Andromeda galaxy, marking a significant milestone in space exploration. This discovery, led by a team from the Indian Institute of Astrophysics (IIA), Bengaluru, has provided fresh insights into stellar phenomena and the dynamic life cycles of stars.
For the first time, astronomers have detected far-ultraviolet emissions from novae—sudden, bright explosions on stars—during their outbursts in the Andromeda galaxy, our closest large galactic neighbour. Using data from the Ultraviolet Imaging Telescope (UVIT) aboard AstroSat, the researchers identified ultraviolet emissions from 42 novae, including four caught in the act of erupting.
Novae occur in binary star systems where a dense, Earth-sized white dwarf star orbits closely with a Sun-like companion. The white dwarf’s strong gravitational pull draws matter from its companion, creating an intense accumulation of material on its surface. This process triggers powerful thermonuclear reactions, producing a sudden bright burst visible as a nova.
The study, published in the Astrophysical Journal, highlights how these explosions contribute to enriching galaxies with new elements. UVIT’s unique ability to observe far and near ultraviolet wavelengths with fine resolution helped track the accretion disks around white dwarfs. These disks, formed from the matter pulled off the companion star, provide insights into the buildup to a nova eruption.
This discovery underscores the importance of future ultraviolet and X-ray missions to unravel the mysteries of novae, advancing our understanding of stellar evolution and galactic chemistry. The findings emphasize the need for continued exploration and observation to uncover more about these fascinating cosmic events