For 10 points give this last name which also identifies an Indian astronomer with a namesake limit.
One person with this name was a short-lived socialist Prime Minister of India who came to power after the quick decline of the V. P. Singh led Janata Dal and was succeed by P. V. Narasimha Rao. Yet another person with this last name notably suffered from polio but took 242 wickets in test cricket as a part of the legendary spin quartet of India. In addition to Bhagwat, another person with this name organized the robbery of a British train at Kakori, and was the commander in chief of the socialist Hindustan Republic Army. That man was better known by his epithet "Azad." Another person with this name introduced a quantity which is equal to the square of the Hartman number and also used the idea of electron degeneracy pressure to give the upper bound of 1.4 solar masses as the maximum mass of a White Dwarf. For 10 points give this last name which also identifies an Indian astronomer with a namesake limit.
One person with this name was a short-lived socialist Prime Minister of India who came to power after the quick decline of the V. P. Singh led Janata Dal and was succeed by P. V. Narasimha Rao.
{Chandrashekhar} [or {Chandrasekar}; prompt on early {Chandra} buzz; prompt on “{Singh}” {during} the first sentence; at any point, accept “{Chandra Shekhar Singh},” “{Bhagwat Chandrashekhar},” “{Chandrashekhar Azad},” or “{Subramanyam Chandrasekhar}”]