Sir

In his Essay “The death of a star” (Nature 438, 1086; 2005) Freeman Dyson pays a well-deserved tribute to astrophysicist Subrahmanyan Chandrasekhar's lifetime of work. Your readers may be interested to know that Wilhelm Anderson of Tartu University in Estonia and Edmund Stoner of the University of Leeds in England separately published white-dwarf mass limits that predated what has come to be known as the ‘Chandrasekhar limit’ (S. Chandrasekhar Astrophys. J. 74, 81–82; 1931).

Anderson (Z. Phys. 1, 851–856; 1929) made the fundamental conceptual coupling of relativity and quantum statistical mechanics that leads to a mass limit. And Stoner (Philos. Mag. 9, 944–963; 1930) produced a robust calculation from first principles and calculated the mass limit for a uniform-density star. The Stoner and Chandrasekhar mass limits differ by 20%, owing to their use of different stellar-density models. But this difference is small, given that the presence of any mass limit at all was the key breakthrough.