astronomy

John Evershed

John Evershed is a astronomy topic covered in the lgStudy science library. This page brings together a partial reference excerpt, illustrations, worked examples, real-world applications and a short study plan, so you can understand John Evershed rather than just read about it. In short: John Evershed CIE FRS FRAS (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.

Key takeaways

John Evershed belongs to astronomy; place it in that map before memorising details.
Learn the definition first, then one example that makes the definition concrete.
Connect John Evershed to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of John Evershed from memory before moving on to harder problems.

Reference excerpt

John Evershed CIE FRS FRAS (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.

Biography 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).

Awards and honours 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.

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 in 1910 and named it after Evershed who had collected the type specimen. In 2015 his archive was acquired by the Science Museum, London.

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

… excerpt ends here. Continue reading the full article.

Illustrations

Worked examples

Example 1 — a first encounter with John Evershed

Start with the simplest possible case. Write down what John Evershed claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In astronomy, the smallest case is usually a single object, a single equation or a single measurement. Check that every symbol or term in your sentence has a meaning in that case.

Example 2 — changing one variable

Take the situation from Example 1 and change exactly one quantity: double it, halve it, or set it to zero. Predict what should happen to John Evershed before you calculate. Comparing your prediction with the result is the fastest way to find out whether you understand the idea or only the words.

Example 3 — an exam-style question

Typical questions about John Evershed ask you to (a) state it precisely, (b) apply it to given data, and (c) explain a limitation. Practise writing all three answers in under five minutes; the third part is what separates a full-mark answer from an average one.

Applications of John Evershed

In research: John Evershed appears in astronomy research whenever the underlying quantities have to be modelled precisely. Papers usually cite it as a starting assumption and then explore where it breaks down.
In technology and industry: Engineering practice reuses John Evershed in design rules, simulations and safety margins. Knowing the idea lets you read a specification sheet and understand why the numbers look the way they do.
In the classroom: John Evershed is common in secondary-school and first-year university syllabi. It links to neighbouring topics 1864 births, 1956 deaths, 20th-century English astronomers, so understanding it makes those chapters shorter.
In everyday life: Look for John Evershed outside the textbook — in sport, cooking, traffic, electronics or the sky above you. An example you found yourself is remembered far longer than one you were given.

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How to study John Evershed in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what John Evershed means in your own words.
Compare your version with the excerpt and mark what you missed.
Work through the three examples above with pen and paper.
Explain John Evershed out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is John Evershed in simple terms?

John Evershed CIE FRS FRAS (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.

Why does John Evershed matter?

Because it connects several astronomy ideas at once: it gives you a definition you can apply, a quantity you can calculate, and a way to check whether a result is plausible.

How should I study John Evershed?

Read the excerpt, restate it from memory, then work through the examples and applications listed on this page. The five-step study plan above takes about twenty minutes.

What does this page cover?

It gives you a compact reference excerpt plus original lgStudy explanations, examples, applications and study material on John Evershed.