In a groundbreaking discovery, astronomers from the Indian Institute of Astrophysics (IIA) have utilized India’s AstroSat to capture ultraviolet (UV) images of nova eruptions in the Andromeda galaxy, marking a significant milestone in the study of binary star systems. This is the first time far-UV emissions from novae have been observed in Andromeda, located 2.5 million light-years away.
What Are Novae?
Novae are extraordinary astronomical events occurring in binary star systems where a white dwarf an Earth-sized, dense star draws material from its companion. This accumulation leads to a thermonuclear explosion on the white dwarf’s surface, resulting in a sudden brightening of the system that fades over weeks or months.
Key Discoveries with AstroSat
The research team, using the Ultraviolet Imaging Telescope (UVIT) onboard AstroSat, observed 42 novae in the Andromeda galaxy, with four of them captured during their explosive outbursts. This unprecedented achievement sheds light on the dynamic life cycles of interacting binary star systems.
UV Observations: The UVIT’s ability to observe in both far-UV (FUV) and near-UV (NUV) simultaneously was instrumental in tracing these phenomena.
Stable Accretion: The study found that the accretion process the accumulation of matter on the white dwarf was stable in these systems, correlating with the brightness of the disc formed by the matter being pulled in.
Significance of the Discovery
The findings, published in The Astrophysical Journal, offer deeper insights into the behavior of binary star systems during different life stages. Scientists can now study systems at various phases some actively accumulating matter, others expelling it into space. The UV outbursts observed are likened to fusion bombs on an astronomical scale, where the explosion brightens the system dramatically and propels material into the interstellar medium.
The study was conducted by a team led by PhD student Judhajeet Basu, alongside Krishnendu S., Sudhanshu Barway, Shatakshi Chamoli, and faculty member GC Anupama from IIA. The institute operates under the Department of Science and Technology (DST), and the project was supported by the Andromeda survey proposals managed by the Indian Space Research Organisation (ISRO).
Future Implications
The success of this study emphasizes the importance of dedicated UV and X-ray missions for exploring the mysteries of stellar systems. Basu highlighted that similar missions in the future could address unanswered questions about novae and other transient astronomical phenomena.
A Step Forward in Astronomical Research
This discovery underscores India’s growing prowess in space-based research and its ability to contribute significantly to the global understanding of complex cosmic events. AstroSat’s advanced capabilities continue to open new frontiers, unraveling the hidden dynamics of the universe.
Indian astronomers are now poised to expand their research, leveraging AstroSat’s precision and embarking on new missions to unravel more celestial secrets.
