  Half of the 2020 Nobel Prize is awarded for discovering a super-massive black
hole at the centre of our Galaxy. One of the first indications of the existence
of a black hole at the centre of a galaxy was found by Jennison and Das Gupta
in 1953 while carrying on a radio observation of the source Cygnus A. Mrinal
Das Gupta, who was doing his PhD at Manchester University at the time of this
discovery, spent the major part of his professional career at Calcutta
University. We give an outline of Das Gupta's life and explain the scientific
significance of his discovery.
