Otto Wilhelm von Struve (May 7, 1819 (

Julian calendar The Julian calendar, proposed by Roman consul Julius Caesar in 46 BC, was a reform of the Roman calendar. It took effect on , by edict. It was designed with the aid of Greek mathematics, Greek mathematicians and Ancient Greek astronomy, as ...

: April 25) – April 14, 1905) was a Russian

astronomer An astronomer is a scientist in the field of astronomy who focuses their studies on a specific question or field outside the scope of Earth. They observe astronomical objects such as stars, planets, moons, comets and galaxies – in either o ...

Baltic German Baltic Germans (german: Deutsch-Balten or , later ) were ethnic German inhabitants of the eastern shores of the Baltic Sea, in what today are Estonia and Latvia. Since their coerced resettlement in 1939, Baltic Germans have markedly declined ...

origins. In Russian, his name is normally given as Otto Vasil'evich Struve (Отто Васильевич Струве). Together with his father, Friedrich Georg Wilhelm von Struve, Otto Wilhelm von Struve is considered a prominent 19th century astronomer who headed the Pulkovo Observatory between 1862 and 1889 and was a leading member of the

Russian Academy of Sciences The Russian Academy of Sciences (RAS; russian: Росси́йская акаде́мия нау́к (РАН) ''Rossíyskaya akadémiya naúk'') consists of the national academy of Russia; a network of scientific research institutes from across t ...

Early years

Struve was born in 1819 in Dorpat (Tartu), then Russian Empire, as the third son out of eighteen sons and daughters of Friedrich Georg Wilhelm von Struve and Emilie Wall (1796–1834). He graduated from a Dorpat gymnasium at the age of 15 and was one year too young by the university rules. Yet, he was admitted to the Imperial University of Dorpat as a listener and completed the program by the age of 20. While studying, he was assisting his father at the Dorpat Observatory. In 1839, he graduated from the university and moved to the newly opened Pulkovo Observatory, where he was immediately appointed as assistant of the director (his father). For his initial observations, he was given the degree of Master of Astronomy by the University of St. Petersburg in 1841. In 1842, he visited Lipetsk for observations of the

solar eclipse A solar eclipse occurs when the Moon passes between Earth and the Sun, thereby obscuring the view of the Sun from a small part of the Earth, totally or partially. Such an alignment occurs during an eclipse season, approximately every six mo ...

and in 1843 defended his PhD.Otto Vasilevich Struve
(in Russian)
(in Russian) In 1843 Otto formally became a Russian subject.

Scientific work

During 1843 and 1844, Struve participated in

longitude Longitude (, ) is a geographic coordinate that specifies the east– west position of a point on the surface of the Earth, or another celestial body. It is an angular measurement, usually expressed in degrees and denoted by the Greek let ...

measurements between Altona,

Greenwich Greenwich ( , ,) is a town in south-east London, England, within the ceremonial county of Greater London. It is situated east-southeast of Charing Cross. Greenwich is notable for its maritime history and for giving its name to the Greenwic ...

and Pulkovo, which were based on large displacement of chronometers over the Earth surface. This newly developed method was adopted in Russia, and from 1844, the longitude was measured starting not from the Tartu Observatory but from the Pulkovo Observatory. Much of the 1844 Struve dedicated to studying the Sun. He deduced its apex coordinates and linear velocity as 7.3 km/s. Although it was significantly smaller than the correct value of 19.5 km/s measured in 1901, Struve's result was correct in that the velocity of the Sun was smaller than that of stars. In 1865 he discovered NGC 8, a double star in the constellation Pegasus. This occurred only 2 days after he discovered the

spiral galaxy Spiral galaxies form a class of galaxy originally described by Edwin Hubble in his 1936 work ''The Realm of the Nebulae''NGC 9 in the constellation Andromeda. Struve explored the constellation of Cassiopeia, finding double stars. He labeled them with his initials in the

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, OΣ in his first catalogue and OΣΣ in his appendix. Struve continued his father's work in several directions. In particular, they compiled famous Pulkovo catalogues of stellar coordinates, including several thousands double stars observed with a 15-inch refractor. Between 1816 and 1852, the observatory completed the famous survey triangulation measurements of the angular arc (named Struve Geodetic Arc). The measurements extended through over 2,820 km, from Hammerfest in

Norway Norway, officially the Kingdom of Norway, is a Nordic country in Northern Europe, the mainland territory of which comprises the western and northernmost portion of the Scandinavian Peninsula. The remote Arctic island of Jan Mayen and t ...

to the Staraya Nekrasovka village by the

Black Sea The Black Sea is a marginal mediterranean sea of the Atlantic Ocean lying between Europe and Asia, east of the Balkans, south of the East European Plain, west of the Caucasus, and north of Anatolia. It is bounded by Bulgaria, Georgia, ...

, and aimed to establish the exact size and shape of the

Earth Earth is the third planet from the Sun and the only astronomical object known to harbor life. While large volumes of water can be found throughout the Solar System, only Earth sustains liquid surface water. About 71% of Earth's surf ...

. In 1851, while observing a solar eclipse, he concluded that the solar corona and protuberances are physically connected with the Sun rather than being simply an optical effect, as most astronomers then believed. Later in 1860 he suggested a close connection between solar protuberances and flares. Struve also observed

satellite A satellite or artificial satellite is an object intentionally placed into orbit in outer space. Except for passive satellites, most satellites have an electricity generation system for equipment on board, such as solar panels or radioiso ...

s of

Uranus Uranus is the seventh planet from the Sun. Its name is a reference to the Greek god of the sky, Uranus (Caelus), who, according to Greek mythology, was the great-grandfather of Ares (Mars), grandfather of Zeus (Jupiter) and father of Cronu ...

( Ariel and Umbriel, in 1851) and of

Neptune Neptune is the eighth planet from the Sun and the farthest known planet in the Solar System. It is the fourth-largest planet in the Solar System by diameter, the third-most-massive planet, and the densest giant planet. It is 17 time ...

. He also measured the rings of

Saturn Saturn is the sixth planet from the Sun and the second-largest in the Solar System, after Jupiter. It is a gas giant with an average radius of about nine and a half times that of Earth. It has only one-eighth the average density of Earth; ...

and discovered (in parallel with other researchers) the dark inner ring of Saturn. In 1861, in his report to the Academy of Sciences, he had supported and developed the ideas of

William Herschel Frederick William Herschel (; german: Friedrich Wilhelm Herschel; 15 November 1738 – 25 August 1822) was a German-born British astronomer and composer. He frequently collaborated with his younger sister and fellow astronomer Carolin ...

that stars are formed from the diffuse matter.V. K. Abalkin ''et al.'
Struve dynasty
(in Russian), St. Petersburg University In 1872, Struve organized assistance with equipment to the newly opened observatory in

Tashkent Tashkent (, uz, Toshkent, Тошкент/, ) (from russian: Ташкент), or Toshkent (; ), also historically known as Chach is the capital and largest city of Uzbekistan. It is the most populous city in Central Asia, with a population of ...

– a southern location offering clear skies for observations. In 1874, he prepared several expeditions to monitor the transit of

Venus Venus is the second planet from the Sun. It is sometimes called Earth's "sister" or "twin" planet as it is almost as large and has a similar composition. As an interior planet to Earth, Venus (like Mercury) appears in Earth's sky never f ...

across the solar disk in eastern Asia, Caucasus, Persia and Egypt. In 1887, he sent several groups within Russia to observe the solar eclipse. In some of those expeditions, he took part personally. In 1885, a 30-inch

refracting telescope A refracting telescope (also called a refractor) is a type of optical telescope that uses a lens as its objective to form an image (also referred to a dioptric telescope). The refracting telescope design was originally used in spyglasses and ...

was installed at Pulkovo, at the time the largest in the world (see great refractor).

Administration

Around 1845, von Struve's father withdrew from most management activities at the Pulkovo Observatory and focused on individual research. From then on, most of administrative duties fell on von Struve, especially in 1858 when his father was gravely ill. With his father's retirement in 1862, Otto officially became director and kept that position for 27 years until 1889. In the mid-1860s, the son's health deteriorated as well, to the point that neither he nor his physician hoped for recovery. However, instead of retiring, von Struve spent a full winter on leave in Italy and managed to restore his health. Struve remained a top authority at the Russian Academy and his requests, e.g. regarding staff appointments were always granted. The first refusal, in 1887, disappointed Struve so much that he applied for resignation and was stopped from that only by the Tsar Alexander III, who requested Struve to keep his posts until the 50th anniversary of the Pulkovo Observatory in 1889. For most of those years, the working language of the Pulkovo Observatory was German, as the staff members were largely foreigners. Struve had only limited command of Russian, yet he used it whenever possible.

Visit to the United States

Otto was the first scientist of the Struve family to visit United States (in 1879: New York, Chicago and San Francisco). The visit served several purposes, including ordering the

Alvan Clark & Sons Alvan Clark & Sons was an American maker of optics that became famous for crafting lenses for some of the largest refracting telescopes of the 19th and early 20th centuries. Founded in 1846 in Cambridgeport, Massachusetts, by Alvan Clark (1804&n ...

optics for the new 30-inch telescope in Pulkovo, and it was a part of long-term Russia-US astronomy partnership during the 19th century. Within that collaboration, many American astronomers stayed at Pulkovo for observations and exchanged data with Russian scientists by mail. By the initiative of Struve, two US astronomers,

Simon Newcomb Simon Newcomb (March 12, 1835 – July 11, 1909) was a Canadian– American astronomer, applied mathematician, and autodidactic polymath. He served as Professor of Mathematics in the United States Navy and at Johns Hopkins University. Born in ...

and Asaph Hall were appointed as Foreign Members of the Russian Academy of Sciences.

Personal life and late years

Struve was married twice. His first wife was a daughter of German emigrants Emilie Dyrssen (1823–1868). They had four sons and two daughters who reached mature age. A few years after her death, Struve married Emma Jankowsky (1839–1902) and had another daughter with her. Two of his younger sons,

Hermann Struve Karl Hermann von Struve ( – 12 August 1920) was a Baltic German astronomer. In Russian, his name is sometimes given as ''German Ottovich Struve'' (Герман Оттович Струве) or ''German Ottonovich Struve'' (Герман Отто� ...

and Ludwig Struve, continued the traditions of the Struve family and became distinguished astronomers. Of the older sons, one served at the Ministry of Finances and another was geologist. After retirement in 1889, Otto Wilhelm Struve stayed mostly in St. Petersburg, summarizing his observations and keeping correspondence with colleagues. He occasionally visited Switzerland and Italy. During his 1895 trip to Germany, he fell ill to the point of abandoning any further travel. He stayed in Germany and died in 1905 in

Karlsruhe Karlsruhe ( , , ; South Franconian German, South Franconian: ''Kallsruh'') is the List of cities in Baden-Württemberg by population, third-largest city of the German States of Germany, state (''Land'') of Baden-Württemberg after its capital o ...

Awards and honors

Struve won the Gold Medal of the Royal Astronomical Society in 1850 for his work on "The Determination of the Constant of Precession with respect to the Proper Motion of the Solar System" published in 1840 . He was a member of the Royal Swedish Academy of Sciences. Between 1852 and 1889, he was also a member of the

and became an academician in 1856. In 1874 he became foreign member of the

Royal Netherlands Academy of Arts and Sciences The Royal Netherlands Academy of Arts and Sciences ( nl, Koninklijke Nederlandse Akademie van Wetenschappen, abbreviated: KNAW) is an organization dedicated to the advancement of science and literature in the Netherlands. The academy is housed ...

. The

asteroid An asteroid is a minor planet of the Solar System#Inner solar system, inner Solar System. Sizes and shapes of asteroids vary significantly, ranging from 1-meter rocks to a dwarf planet almost 1000 km in diameter; they are rocky, metallic o ...

768 Struveana 768 Struveana is a minor planet orbiting the Sun. The asteroid was named jointly in honor of Baltic German astronomers Friedrich Georg Wilhelm von Struve, Otto Wilhelm von Struve Otto Wilhelm von Struve (May 7, 1819 (Julian calendar: April 25) ...

was named in honor of Otto Wilhelm, Friedrich Georg Wilhelm and

Karl Hermann Struve Karl Hermann von Struve ( – 12 August 1920) was a Baltic German astronomer. In Russian, his name is sometimes given as ''German Ottovich Struve'' (Герман Оттович Струве) or ''German Ottonovich Struve'' (Герман Отто� ...

; and a lunar crater was named for another 3 astronomers of the Struve family: Friedrich Georg Wilhelm, Otto Wilhelm and

Otto Otto is a masculine German given name and a surname. It originates as an Old High German short form (variants ''Audo'', '' Odo'', '' Udo'') of Germanic names beginning in ''aud-'', an element meaning "wealth, prosperity". The name is recorde ...

. The Struve Geodetic Arc was included to the

World Heritage List A World Heritage Site is a landmark or area with legal protection by an international convention administered by the United Nations Educational, Scientific and Cultural Organization (UNESCO). World Heritage Sites are designated by UNESCO for h ...

in 2005.Struve Geodetic Arc
UNESCO

Early years

Scientific work

Administration

Visit to the United States

Personal life and late years

Awards and honors

See also

References

Further reading