# Edmund C. Stoner and the Discovery of the Maximum Mass of White Dwarfs

**By Michael Nauenberg, University of California, Santa Cruz**

Based on solid theoretical foundations, Stoner then calculated the properties of white dwarfs for arbitrary densities, and obtained the critical mass in the limit that the density approaches infinity. His paper, “The Equilibrium of White Dwarfs,” appeared in 1930—a year before publication of Chandrasekhar’s first short paper on his calculation of the critical mass. Chandrasekhar acknowledged that his result was in “agreement” with Stoner’s, but he also claimed, without giving a valid proof, that the critical mass was a maximum. But this result had already been demonstrated by Stoner, who had shown that the mass is a monotonically increasing function of the density, while it took Chandrasekhar several additional months before he found a valid argument for this conclusion and he was able to show that the density becomes infinite to Stoner, he claimed that “they had never examined the ramifications” of the relativistic equation of state. With regard to Stoner, however, this claim is incorrect. In his 1983 Nobel prize lecture, Chandrasekhar gave a historical review of his work on white dwarfs but did not cite Stoner’s prior work. This universal neglect of Stoner’s seminal work on white dwarfs explains why, with a few notable exceptions, his contributions to the discovery of the maximum mass of white dwarfs have been forgotten until now. n Editor’s Note: Nauenberg’s complete article on Stoner will appear in the May issue of the Journal of the History of Astronomy. at the critical mass. At about the same time, Lev Landau, who was a visitor in Zurich collaborating with Pauli’s assistant, Rudolf Peierls, also evaluated the critical mass.

Stoner was encouraged by Arthur S. Eddington to pursue further the implication of his relativistic equation of state for stellar structure, and he communicated Stoner ’s last two papers on this subject to the Monthly Notices of the Royal Astronomical Society. His correspondence with Stoner deepens the mystery why several years later, in a devastating public attack on Chandrasekhar ’s similar work on white dwarfs, Eddington rejected Stoner’s relativistic equation of state, and its profound implication for the existence of a white dwarf mass limit. Eddington’s criticisms were entirely unfounded, but his enormous prestige led to the acceptance of his views by a majority of the astronomical community, and to the initial rejection of Chandrasekhar’s work.

In Kameshwar Wali’s excellent biography of Chandrasekhar, Stoner is never mentioned. More recently, in his book The Empire of Stars, Arthur Miller remarked, “It was indeed extraordinary that a nineteen-year-old Indian youth had managed to make a discovery that had eluded the great minds of European astrophysics.” Although Miller refers briefly to Anderson and to Stoner, he claimed that “they had never examined the ramifications” of the relativistic equation of state. With regard to Stoner, however, this claim is incorrect. In his 1983 Nobel prize lecture, Chandrasekhar gave a historical review of his work on white dwarfs but did not cite Stoner’s prior work.

This universal neglect of Stoner’s seminal work on white dwarfs explains why, with a few notable exceptions, his contributions to the discovery of the maximum mass of white dwarfs have been forgotten until now.

Editor’s Note: Nauenberg’s complete article on Stoner will appear in the May issue of the Journal of the History of Astronomy.