Who is Bibha Chowdhuri? Indian physicist who studied cosmic rays and had a star named in her honour

Bibha Chowdhuri was an Indian physicist and one of the country's pioneering women researchers in high-energy and particle physics. Born in Calcutta in 1913, she pursued scientific research when women had few opportunities in the field. Her career focused especially on cosmic rays and high-energy particles.

She researched cosmic rays with Debendra Mohan Bose at the Bose Institute, using photographic emulsions to study subatomic-particle tracks. Their findings appeared in Nature between 1938 and the early 1940s. Chowdhuri later completed doctoral research at the University of Manchester and became the first woman researcher at TIFR in 1949.

Chowdhuri died in 1991, with her work still little known outside scientific circles. In 2019, the International Astronomical Union honoured her by naming the star HD 86081 Bibha. The star's name gives her a lasting place in the night sky and connects her legacy with her research on invisible cosmic particles.

HD 86081 Bibha is the official name given to a star in honour of Bibha Chowdhuri. The International Astronomical Union made the naming decision in 2019, long after Chowdhuri's death. It transformed recognition of her scientific work into a permanent astronomical memorial.

The star is located in the constellation Sextans. Its name combines the designation HD 86081 with Bibha, Chowdhuri's first name. The article also explains that “Bibha” means “ray of light” in Bengali. That meaning creates a fitting link with her work on cosmic rays and high-energy particles.

The naming matters because Chowdhuri received limited public recognition during her lifetime. Her research was not widely celebrated outside scientific circles, even though it contributed to early particle studies. By placing her name in the night sky, the 2019 honour helped bring her contribution to a broader audience and preserved her legacy beyond the institutions where she worked.

Chowdhuri's career was highly unusual for an Indian woman of her era. Scientific research was largely dominated by men, and opportunities for women were limited. Yet she completed advanced physics training and continued into specialised research rather than leaving the field after university.

Her master's degree at the University of Calcutta shows the scale of that barrier. In 1936, she was reportedly the only woman in a class of 24 students. She then researched cosmic rays with Debendra Mohan Bose, completed a PhD at the University of Manchester, and joined major research institutions.

Her 1949 appointment as the first woman researcher at the Tata Institute of Fundamental Research marked another breakthrough. She later worked at the Physical Research Laboratory in Ahmedabad. Although her contributions were not widely recognised during her lifetime, her path demonstrated that women could participate in advanced Indian and international physics research despite strong institutional and social obstacles.

Cosmic rays are high-energy particles that travel through space and interact with Earth's atmosphere. They became a useful subject for Chowdhuri and Debendra Mohan Bose because their interactions could reveal evidence about tiny particles that cannot be seen directly.

At the Bose Institute, the researchers used photographic emulsions. When subatomic particles passed through these materials, they left tracks. Scientists could examine those tracks to identify particle behaviour and investigate which kinds of particles were involved. Chowdhuri and Bose used this method in research published in Nature between 1938 and the early 1940s.

This approach helped connect cosmic-ray events with early studies of mesons, a family of subatomic particles. Their work was later limited by a shortage of sensitive photographic plates during the Second World War. Even so, the experiments formed part of the early effort to use cosmic rays as a window into high-energy particle physics.

Chowdhuri and Bose contributed to meson research by studying the tracks made by cosmic-ray particles. Mesons are a family of subatomic particles, and their work formed part of the early effort to investigate these particles through high-energy events.

Their key tool was photographic emulsion. Cosmic rays travelled through space and interacted with Earth's atmosphere, producing particle events. The emulsions recorded tracks from those subatomic particles. By examining the tracks, the researchers could gather evidence about the particles involved. Their findings were published in Nature between 1938 and the early 1940s.

The work did not complete the study of mesons, but it added evidence during an important early period of particle physics. Further experiments became difficult when sensitive photographic plates grew scarce during the Second World War. Chowdhuri later continued her scientific career in Britain and at Indian research institutions, including TIFR and PRL.

Chowdhuri and Bose's experiments were constrained by a practical wartime problem. During the Second World War, sensitive photographic plates became scarce. These plates were essential to their method because they captured the tracks left by subatomic particles.

Without enough plates, the researchers could not continue collecting and analysing particle tracks as freely as before. The shortage therefore limited further experiments, even though their research had already contributed to early investigations into mesons. Their published findings had appeared in Nature between 1938 and the early 1940s.

Chowdhuri did not abandon physics after this setback. She later travelled to the University of Manchester, where she pursued a PhD under physicist Patrick Maynard Stuart Blackett. Her career continued at TIFR and the Physical Research Laboratory, where she worked on cosmic rays and high-energy particles. The wartime shortage interrupted one research programme, but not her broader scientific career.

Cosmic rays are useful because they are high-energy particles travelling through space and interacting with Earth's atmosphere. Those interactions create events that can reveal the behaviour of subatomic particles. For researchers working before modern facilities were widely available, cosmic rays offered a natural source of high-energy phenomena to investigate.

Chowdhuri and Bose studied these events with photographic emulsions. The particles left visible tracks in the emulsions, giving scientists physical evidence to examine. Track patterns helped them identify and investigate subatomic particles, including mesons. Their work contributed to early meson studies and was published in Nature between 1938 and the early 1940s.

The method depended on specialised materials, so it had limits. A wartime shortage of sensitive photographic plates restricted further experiments. Even with that interruption, cosmic-ray research helped build knowledge of high-energy particles and supported Chowdhuri's later work at institutions including TIFR and the Physical Research Laboratory.