Chandrasekhar, Subrahmanyan (1910–1995)

Indian-born US astrophysicist who was awarded the Nobel Prize for Physics in 1983 for his theoretical studies of the physical processes in connection with the structure and evolution of stars. The Chandrasekhar limit is the maximum mass of a white dwarf before it turns into a neutron star.

Chandrasekhar has also investigated the transfer of energy in stellar atmospheres by radiation and convection, and the polarization of light emitted from particular stars.

Chandrasekhar was born in Lahore (now in Pakistan) and studied at Presidency College in Madras (now Chennai), India, graduating with a BA in 1930, and then at Cambridge University, England, where he gained a PhD in theoretical physics. He joined the staff of the University of Chicago, Illinois, 1936, becoming a professor there in 1952.

The evolution of white dwarfs is explained in his Introduction to the Study of Stellar Structure (1939). He calculated that stellar masses below 1.44 times that of the Sun would form stable white dwarfs, but those above this limit would not evolve into white dwarfs; the limit is now believed to be about 1.2 solar masses. Stars with masses above the Chandrasekhar limit are likely to explode into supernovae; the mass remaining after the explosion may form a white dwarf if the conditions are suitable, but is more likely to form a neutron star.