On this day, 19th October: Subrahmanyan Chandrasekhar: The Visionary Astrophysicist Born

On October 19, 1910, Subrahmanyan Chandrasekhar, an eminent Indian-American astrophysicist, was born in Lahore, India (now Pakistan). Renowned for his groundbreaking work in stellar evolution, particularly his formulation of the Chandrasekhar limit, he significantly advanced our understanding of white dwarfs and black holes. His contributions to theoretical physics earned him the Nobel Prize in Physics in 1983, shared with William A. Fowler, for their studies on the physical processes important to the structure and evolution of stars.

Early Life and Education

Chandrasekhar was born into a Tamil family and showed an early aptitude for science. He pursued his undergraduate studies at Presidency College in Madras (now Chennai) from 1925 to 1930, where he developed a keen interest in physics. He then moved to Trinity College, Cambridge, for further studies, earning his Ph.D. in 1933 under the supervision of R.H. Fowler.

Major Contributions

1. Chandrasekhar Limit: In 1930, during his voyage to England, he proposed that a white dwarf star could not exceed a mass of approximately 1.44 times that of the Sun. If it did, it would collapse into a neutron star or black hole. This concept became known as the Chandrasekhar limit and is fundamental to modern astrophysics.
2. Stellar Structure and Evolution: His extensive research on stellar dynamics and radiative transfer has shaped our understanding of how stars evolve over time. His theoretical models laid the groundwork for future studies on supernovae and neutron stars.
3. Publications and Influence: Chandrasekhar authored numerous influential books and papers throughout his career, including An Introduction to the Study of Stellar Structure (1939) and The Mathematical Theory of Black Holes (1983). He also served as editor for The Astrophysical Journal, enhancing its reputation as a leading scientific publication.

Legacy

Chandrasekhar's work has had a lasting impact on both theoretical physics and astronomy. He became a U.S. citizen in 1953 after moving to the United States in 1937, where he spent most of his career at the University of Chicago. His legacy is commemorated through various honors, including the naming of NASA's Chandra X-ray Observatory in his honor.