John Evershed CIE FRS FRAS (26 February 1864 – 17 November 1956) was an English

astronomer An astronomer is a scientist in the field of astronomy who focuses on a specific question or field outside the scope of Earth. Astronomers observe astronomical objects, such as stars, planets, natural satellite, moons, comets and galaxy, galax ...

. He was the first to observe radial motions in

sunspot Sunspots are temporary spots on the Sun's surface that are darker than the surrounding area. They are one of the most recognizable Solar phenomena and despite the fact that they are mostly visible in the solar photosphere they usually aff ...

s, a phenomenon now known as the Evershed effect.

Biography

Evershed was born in Gomshall,

Surrey Surrey () is a Ceremonial counties of England, ceremonial county in South East England. It is bordered by Greater London to the northeast, Kent to the east, East Sussex, East and West Sussex to the south, and Hampshire and Berkshire to the wes ...

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 The spectroheliograph is an instrument used in astronomy which captures a photography, photographic image of the Sun at a single wavelength of light, a monochromatic image. The wavelength is usually chosen to coincide with a optical spectrum, spec ...

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 The Royal Observatory, Greenwich (ROG; known as the Old Royal Observatory from 1957 to 1998, when the working Royal Greenwich Observatory, RGO, temporarily moved south from Greenwich to Herstmonceux) is an observatory situated on a hill in G ...

at Herstmonceux. In the autumn of 1890 was a founding member of the

British Astronomical Association The British Astronomical Association (BAA) was formed in 1890 as a national body to support the UK's amateur astronomers. Throughout its history, the BAA has encouraged observers to make scientifically valuable observations, often in collaborat ...

. He directed its Solar Spectroscopy Section (1893-1899) and Spectroscopic Section (1924-1926).

Awards and honours

In 1894 Evershed was elected a Fellow of the

Royal Astronomical Society The Royal Astronomical Society (RAS) is a learned society and charitable organisation, charity that encourages and promotes the study of astronomy, planetary science, solar-system science, geophysics and closely related branches of science. Its ...

, in 1918 he was awarded the

Gold Medal of the Royal Astronomical Society The Gold Medal of the Royal Astronomical Society is the highest award given by the Royal Astronomical Society (RAS). The RAS Council have "complete freedom as to the grounds on which it is awarded" and it can be awarded for any reason. Past awar ...

. He was elected a

Fellow of the Royal Society Fellowship of the Royal Society (FRS, ForMemRS and HonFRS) is an award granted by the Fellows of the Royal Society of London to individuals who have made a "substantial contribution to the improvement of natural science, natural knowledge, incl ...

in May, 1915. The Evershed crater on the

Moon The Moon is Earth's only natural satellite. It Orbit of the Moon, orbits around Earth at Lunar distance, an average distance of (; about 30 times Earth diameter, Earth's diameter). The Moon rotation, rotates, with a rotation period (lunar ...

is named in his honor. He was awarded as a Companion of the Indian Empire on his retirement in 1923.

Personal life

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. He died in Ewhurst, Surrey on 17 November 1956. He also had interest in lepidoptera and other insects. W. H. Evans described a butterfly ''

Thoressa evershedi ''Thoressa evershedi'', the Evershed's ace, is a butterfly belonging to the family Hesperiidae.William Harry Evans, W. H. Evans described it from Palni Hills in 1910 and named it after John Evershed, Evershed as he was the first person to collect ...

'' in 1910 and named it after Evershed who had collected the

type Type may refer to: Science and technology Computing * Typing, producing text via a keyboard, typewriter, etc. * Data type, collection of values used for computations. * File type * TYPE (DOS command), a command to display contents of a file. * ...

specimen. In 2015 his archive was acquired by the

Science Museum, London The Science Museum is a major museum on Exhibition Road in South Kensington, London. It was founded in 1857 and is one of the city's major tourist attractions, attracting 3.3 million visitors annually in 2019. Like other publicly funded ...

Bibliography

Monthly Notices of the Royal Astronomical Society *''Report of his Observatory.'' vol. 94 (1934), p. 318 *''Report of his Observatory.'' vol. 95 (1935), p. 379 *''Report of his Observatory.'' vol. 96 (1936), p. 337 *''Report of his Observatory.'' vol. 97 (1937), p. 327 *''Report of his Observatory.'' vol. 98 (1938), p. 296 *''Report of his Observatory.'' vol. 100 (1940), p. 298 *''Report of his Observatory.'' vol. 102 (1942), p. 94 *''Report of his Observatory.'' vol. 103 (1943), p. 84 *''Report of his Observatory.'' vol. 105 (1945), p. 122 *''Report of his Observatory.'' vol. 106 (1946), p. 59 *''Report of his Observatory.'' vol. 107 (1947), p. 81 *''Report of his Observatory.'' vol. 108 (1948), p. 78 *''Report of his Observatory.'' vol. 109 (1949), p. 177 *''Report of his Observatory.'' vol. 110 (1950), p. 164 *''Report of his Observatory.'' vol. 111 (1951), p. 216 Nature *''The Chromosphere.'' vol. 37 (1887), p. 79 *''The Corona Spectrum.'' vol. 48 (1893), p. 268 *''A Remarkable Flight of Birds.'' vol. 52 (1895), p. 508 *''The Corona Spectrum.'' vol. 56 (1897), p. 444 *''Solar Radiation.'' vol. 58 (1898), p. 619 *''Absorption Markings in “K” Spectroheliograms. '' vol. 86 (1911), p. 348 *''Absorption Markings in “K” Spectroheliograms. '' vol. 87 (1911), p. 111 *''Butterfly Migration in Relation to Mimicry.'' vol. 89 (1912), p. 659 *''Luminous Halos surrounding Shadows of Heads.'' vol. 90 (1913), p. 592 *''The Green Flash.'' vol. 95 (1915), p. 286 *''A Question of Albedo.'' vol. 96 (1915), p. 369 *''Scarcity of Wasps in Kashmir in 1916.'' vol. 99 (1917), p. 185 *''Observations of Nova Aquilæ in India.'' vol. 102 (1918), p. 105 *''The Magnetic Storm of August 11–12, 1919.'' vol. 104 (1920), p. 436 *''Terrestrial Magnetic Disturbances and Sun-spots.'' vol. 108 (1921), p. 566 *''Optical Definition and Resolving Power.'' vol. 110 (1922), p. 179 *''The Green Flash at Sunset.'' vol. 111 (1923), p. 13 *''An Uncommon Type of Cloud.'' vol. 112 (1923), p. 901 *''Photographic Studies of Solar Prominences.'' 116 (1925), p. 30 *''Letter to Editor.'' vol. 116 (1925), p. 395 *''The ‘Green Flash’.'' vol. 120 (1927), p. 876 Journal of the British Astronomical Association, *''The Distribution of the Solar Prominence of 1891.'' vol. 2 (1892), p. 174 *''Some recent attempts to photograph the Faculae and Prominences.'' vol. 3 (1893), p. 269 *''The Cause of the Darkness of Sun Spots.'' vol. 7 (1897), p. 190 *''A New Arrangement of Prisms for a Solar Prominence Spectroscope.'' vol. 7 (1897), p. 331 The Observatory *''The Flash-Spectrum.'' vol. 25 (1902), p. 198 *''The Flash-Spectrum.'' vol. 25 (1902), p. 272 *''Sun-Spots and Magnetic Storms.'' vol. 27 (1904), p. 129 *''The Rumford Spectrograph of the Yerkes Observatory.'' vol. 27 (1904), p. 164 *''Sun-Spots and Solar Temperature.'' vol. 31 (1908), p. 462 *''Helium Absorption in the Sun.'' vol. 31 (1908), p. 212 *''Water-Vapour Lines in the Spot-Spectrum.'' vol. 32 (1909), p. 101 *''Sun-spots and the Solar Temperature.'' vol. 32 (1909), p. 135 *''Pressure in the Reversing Layer.'' vol. 32 (1909), p. 254 *''Radial Movement in Sun-spots.'' vol. 32 (1909), p. 291 *''Pressure in the Reversing Layer.'' vol. 32 (1909), p. *''Dante and Mediaeval Astronomy (with Evershed, M. A.).'' vol. 34 (1911), p. 440 *''Radium and the Chromosphere.'' vol. 35 (1912), p. 360 *''Some Problems of Astronomy (XIV The Displacement of the Lines of the Solar Spectrum Towards the Red).'' vol. 37 (1914), p. 124 *''The General Shift of Fraunhofer Lines Towards the Red.'' vol. 37 (1914), p. 388 *''Anomalous Dispersion in the Sun.'' vol. 39 (1916), p. 59 *''Large Prominences.'' vol. 39 (1916), p. 392 *''Anomalous Dispersion in the Sun.'' vol. 39 (1916), p. 432 *''The Einstein Effect and the Eclipse of 1919 May 29.'' vol. 40 (1917), p. 269 *''Day and Night "Seeing".'' vol. 40 (1917), p. 407 *''The Displacement of the Cyanogen Bands in the Solar Spectrum.'' vol. 41 (1918), p. 371 *''The Positive-on-Negative Method of Measuring Spectra.'' vol. 41 (1918), p. 443 *''The Displacement of the Solar Lines Reflected by Venus.'' vol. 42 (1919), p. 51 *''Calcium Clouds in the Milky Way.'' vol. 42 (191), p. 85 *''The Pulsation Theory of Cepheid Variables.'' vol. 42 (1919), p. 124 *''The Moon in Daylight.'' vol. 42 (1919), p. 339 *''Displacement of the Lines in the Solar Spectrum and Einstein's Prediction.'' vol. 43 (1920), p. 153 *''The Relativity Shift in the Solar Spectrum.'' vol. 44 (1921), p. 243 *''The Spectrum of Sirius.'' vol. 45 (1922), p. 296 *''The Einstein Effect in the Solar Spectrum.'' vol. 46 (1923), p. 299 *''Stationary Calcium in Space.'' vol. 47 (1924), p. 53 *''The Height of the Chromosphere.'' vol. 48 (1925), p. 45 *''The Height of the Chromosphere.'' vol. 48 (1925), p. 146 *''The Green Flash.'' vol. 49 (1926), p. 369 *''Recent Work at Arcetri (with Evershed, M. A.).'' vol. 55 (1932), p. 254 *''The Central Intensities of the Fraunhofer Lines.'' vol. 56 (1933), p. 275 *''The Problem of the Red Shift in the Solar Spectrum.'' vol. 60 (1937), p. 266 *''Obituary: George Ellery Hale.'' vol. 61 (1938), p. 163 *''Sunspots and Magnetic Storms.'' vol. 63 (1940), p. 47 *''The Magnetic Effect in Sunspot Spectra.'' vol. 65 (1944), p. 190 *''Spectrum Lines in Chromospheric Flares.'' vol. 68 (1948), p. 67 *''The Central Intensities of the Fraunhofer Lines.'' vol. 69 (1949), p. 109

References

External links

J. Evershed
@

Astrophysics Data System The SAO/NASA Astrophysics Data System (ADS) is a digital library portal for researchers on astronomy and physics, operated for NASA by the Smithsonian Astrophysical Observatory. ADS maintains three bibliographic collections containing over 15 ...

{{DEFAULTSORT:Evershed, John 1864 births 1956 deaths People from Gomshall 20th-century English astronomers Recipients of the Gold Medal of the Royal Astronomical Society Fellows of the Royal Society