Leon Mestel obituary

Astronomer and astrophysicist who inspired generations of students and discovered the cooling law for white dwarf stars

Leon Mestel, who has died aged 90, taught generations of astronomers the importance of magnetic fields inside stars and, on the larger scale, across galaxies. He discovered the cooling law for white dwarf stars, showed how magnetic fields in forming stars allowed them to dispose of excess spin, and how a star such as the sun slows down its rotation through an interaction between the star's magnetic field and the wind of hot gas blowing from its surface.

He was associated with the universities of Cambridge, Manchester and especially Sussex, and played a major role in helping to develop the Astronomy Centre at Sussex.