S Chandrasekhar India’s lesser-known star
Known for his study of black holes and how stars collapse under their gravity to reach infinite density, Subrahmanyan Chandrasekhar was one of the 20th century’s most prominent astrophysicists. Born in 1910 in Lahore, Chandrasekhar, or ‘Chandra’, spent his professional life in the US.
He won the Nobel Prize for Physics in 1983 for theoretical studies of the physical processes of importance to the structure and evolution of the stars, along with William A Fowler, who helped him publish a paper in the Proceedings of the Royal Society of London, the first of about 400 articles – and 10 books, which became his life’s work.
Chandra’s father was a government official, while his mother a litterateur. He’s also the nephew of legendary Indian physicist Sir CV Raman. Chandra theorised many concepts and inventions, the most prominent being the “Chandrasekhar Limit”, which defined the maximum mass of a dwarf star set at 1.39 (~1.4) times the mass of the Sun (1.988 × 1030 kg), which is 2.765 × 1030 kg.
Up to this limit, the white dwarf stars remain stable, after which they become black holes on collapse following a supernova. He calculated the limit during his first voyage in 1930 from India to Cambridge University, for his graduation. Over the decades, Chandra’s work on the collision of stars became reality when the Event Horizon Telescope released two pictures of black holes that were born out of dead stars.
A lesser-known fact about Chandra is that his theoretical physicist expertise in hydrodynamics led Robert Oppenheimer to invite him to join the Manhattan Project at Los Alamos, but delays in the processing of his security clearance prevented him from contributing to the project. In 1979, NASA named the third of its four Great Observatories after Chandrasekhar.
The Chandra X-ray Observatory was deployed by Space Shuttle Columbia on July 23, 1999. In 1937, Chandra joined the faculty of the University of Chicago, where he taught until his death on August 21, 1995, at the age of 84, from a heart attack.