John Evershed

English astronomer

John Evershed CIE FRS (26 February 1864 – 17 November 1956) was an English astronomer. He was the first to observe radial motions in sunspots, a phenomenon now known as the Evershed effect.

Evershed was born in Gomshall, Surrey to John and Sophia (née Price) Evershed. He made the discovery which bears his name while at Kodaikanal Observatory in 1909. After retirement in 1923 he set up a private observatory at Ewhurst, Surrey and built a large spectroheliograph of special design and another with high dispersion liquid prism. He continued to study the wave lengths of H and K lines in prominences, giving values of the solar rotation at high levels in different latitudes and at different phases of the solar cycle. Work continued until 1950 when the observatory closed and he presented some of his instruments to the Royal Greenwich Observatory at Herstmonceux. In the autumn of 1890 was a founding member of the British Astronomical Association. He directed its Solar Spectroscopy Section (1893 1899) and Spectroscopic Section (1924 1926).

In 1894 Evershed was elected a Fellow of the Royal Astronomical Society, in 1918 he was awarded the Gold Medal of the Royal Astronomical Society. He was elected a Fellow of the Royal Society in May, 1915. The Evershed crater on the Moon is named in his honor. He was awarded as a Companion of the Indian Empire on his retirement in 1923.

Evershed married fellow astronomer Mary Acworth Orr Evershed on 4 September 1906 at Claughton near Scarborough, Yorkshire. Following the death of his wife in 1949 he married Margaret Randall in 1950. W. H. Evans described a butterfly Thoressa evershedi in 1910 and named it after Evershed who had collected the type specimen. In 2015 his archive was acquired by the Science Museum, London.