Otto Struve
Encyclopedia
Otto Struve was a Russian astronomer. In Russian, his name is sometimes given as Otto Lyudvigovich Struve (Отто Людвигович Струве); however, he spent most of his life and his entire scientific career in the United States
. Otto was the descendant of famous astronomers of the Struve family
; he was the son of Ludwig Struve
, grandson of Otto Wilhelm von Struve
and great-grandson of Friedrich Georg Wilhelm von Struve
. He was also the nephew of Karl Hermann Struve.
With more than 900 journal articles and books, Struve was one of the most distinguished and prolific astronomers of the mid-20th century. He served as director of Yerkes
, McDonald
, Leuschner
and National Radio Astronomy Observatories
and is credited with raising world-wide prestige and building schools of talented scientists at Yerkes and McDonald observatories. In particular, he hired Subrahmanyan Chandrasekhar
and Gerhard Herzberg
who later became Nobel Prize
winners. Struve's research was mostly focused on binary
and variable star
s, stellar rotation
and interstellar matter. He was one of the few eminent astronomers in the pre-Space Age era to publicly express a belief that extraterrestrial intelligence was abundant, and so was an early advocate of the search for extraterrestrial life.
, then Russian Empire
, as the first child of Ludwig Struve and Elizaveta Khrystoforovna Struve (1874–1964). His astronomy experience started early: from the age of eight, he was accompanying father in the telescope tower and from 10 carried out some minor observations, despite his fear of the dark spaces. After having received home education, at the age of 12, Struve started attending a gymnasium in Kharkiv and showed mathematical talents. Otto was the first child of the Struve family in Russia who attended a Russian-speaking rather than German-speaking school, and was bilingual in German and Russian. After graduating in 1914, he continued his astronomy work. In June 1914, Struve took part in preparations for observation of a total solar eclipse (August 8, 1914) and later used that experience and results for his masters degree work defended in 1919 at Kharkiv University.
Struve entered the Kharkiv University in 1915, at the time of political unrest and wars in Russia. In the beginning of 1916, just having finished the first semester, he interrupted his studies and enlisted to a military artillery school in St. Petersburg. He passed an accelerated training program, and in February 1917, was sent to the Turkish front. After the Treaty of Brest-Litovsk
was signed, Struve returned to Kharkiv for a year between spring 1918 and spring 1919 and completed a full university course. in June 1919, he received a certificate signed by the rector of Kharkiv University stating that Struve will stay with the University to prepare for professorship at the department of astronomy and geodesics. During that time, Struve also worked at the "workshop school of fine mechanics" and obtained a license of a workshop trainer. The workshop was organized by his father with the goal of creating traditions of astronomy engineers in Russia. Those were non-existent and foreign engineers were personally invited from abroad for high-quality mechanical work.
took its toll. To avoid repressions of the Bolsheviks, his family had to move from Kharkiv to Sevastopol
which was still under control of the White Army. There, a series of tragedies took away most of the family: the youngest sister Elizabeth drowned, brother Werner died from tuberculosis
, and father was taken by a stroke on November 4, 1920. Whereas his mother and sister returned to Kharkiv, on November 16–17, 1920, Otto followed the escaping Wrangel's Army
. With a military transport, he escaped from Sevastopol to Turkey and never returned to Russia since then. He was later invited several times to conferences in the Soviet Union, but for various reasons declined to attend.
During the year and a half that Otto spent in exile in Gallipoli
and later in Constantinople
, he became an impoverished refugee, eating at relief agencies and taking any job he could find. For some time, he worked as a woodcutter, sleeping with fellow Russian officers, 6 people in a tent. One night, a neighboring tent was hit by lightning, killing everyone inside. Struve wrote to his uncle Hermann Struve
in Germany for assistance, without knowing that the latter had died a few months earlier, on August 12, 1920. However, the widow of Hermann, Eva Struve, contacted Paul Guthnick, her late husband's successor at the Berlin-Babelsberg Observatory
. Germany itself was suffering after the wars, and there was little chance to obtain a position for a Russian there. Therefore, Guthnick wrote, on December 25, 1920, to the director of Yerkes Observatory
in Chicago
Edwin B. Frost asking position for Struve. He received a reply on January 27, 1921, where Frost promised to do his best. On March 2, 1921, Frost wrote to Struve, offering him a position at Yerkes. Given his situation in Turkey, it was a lucky chance that Struve received that letter. On March 11, Struve sent a reply, thanking for the offer and accepting it. The letter was formally written in English but with German grammar, revealing the poor English proficiency of Struve (When they later met in US, they spoke in German). Struve also acknowledged that he had no experience in spectral astrophysics. Nevertheless, when applying for his position, Frost mentioned that "I am perfectly willing to take him on his lineage .. We regard Otto Struve as first-class spectroscopist and astrophysicist " and that his degree in Kharkiv was equivalent to a doctor degree (which Struve never claimed and which was hardly so). It took several months to arrange for travel documents and funding. In late August 1921, Struve received his visa and travel tickets at the US Consulate in Turkey. In September, he boarded S.S. Hog Island and on October 7, 1921, arrived in New York. He was met there, put on the train, and 2 days later arrived in Chicago.
Struve proved to be a quick learner and talented scientist. Five months after arrival, he made his first discovery of a pulsating star at Gamma Ursae Minoris
and wrote an article on it in September 1922. He was spending more time with observations than anyone at Yerkes, trying every telescope available there, also making weather observations at Williams Bay
. On October 24, 1922, he discovered the asteroid
991 McDonalda
and on November 14 of the same year, another asteroid 992 Swasey
.
As early as December 1923, Struve defended his PhD thesis on short-period spectroscopic double star
s at the University of Chicago
. Frost helped him in waiving some required PhD examinations, e.g. in French and German, stating that Struve had done ample reading of scientific literature back in Russia, and was fluent in those languages. Struve then became an instructor (January 1924), assistant professor (1927) and full professor (1932) at the university. His rapid promotion was again assisted by Frost, who also used job-offer letters from other observatories to Struve as proof that Struve was a highly valued scientist who must be kept at Chicago University. Between 1932 and 1947, Struve headed Yerkes Observatory; from 1939 to 1950 he acted as a founding director of the McDonald Observatory
, and from July 1, 1952 to 1962 served as the first director of the National Radio Astronomy Observatory
at University of Virginia
. All those years, he remained in America except for conferences and an 8-month sabbatical leave to Cambridge University between August 1928 and May 1929. He applied for and won a Guggenheim Fellowship
to cover his travel to, and living expenses in, Cambridge. While in Cambridge, Struve mostly worked on interstellar matter; he also went on a short trip to Leiden to meet Jan Oort
.
Struve was a highly successful administrator who brought fame to Yerks Observatory and rebuilt the astronomy department of the University of Chicago. In particular, he gradually renewed the scientific staff, dismissing stagnated permanent researchers who were not making significant contributions to science but were occupying the faculty positions. The process was difficult. Struve used to arrive first and leave last from the observatory, taking notes on working hours of staff which he then used in his bureaucratic moves. In replacement, he hired several young and talented researchers who later became world-famous scientists. Those included Subrahmanyan Chandrasekhar
(Nobel Prize in Physics
in 1983), Gerard Kuiper
(protagonist of the famous Kuiper Prize), Bengt Strömgren
, Gerhard Herzberg
(Nobel Prize in Chemistry
in 1971), William Wilson Morgan
and Jesse L. Greenstein
. After World War II, he also invited a number of leading European researchers, such as Pol Swings
, Jan Oort
(father of radio astronomy
), Marcel Minnaert
, H. C. van der Hulst and Albrecht Unsöld
. As most of them were foreigners, their appointment met strong opposition from the science officials for various reasons, such as taking jobs from Americans during the Great Depression
. India-born Chandrasekhar, who stayed in the Soviet Union, was also suspected of Communist connections. Struve spent extraordinary efforts defending and justifying each case, and those efforts paid off in building the scientific school at Yerkes and Chicago University. For example, Chandrasekhar spent his entire career as a scientist and administrator at Chicago University, assisting Struve and eventually replacing him as president of the American Astronomical Society
(from 1949) and as the Editor in Chief of the Astrophysical Journal
.
By the late 1940s, many young researchers whom Struve invited to Yerkes became established scientists. This created friction, as they did not want to follow his every word and were building their own careers. In 1947, Struve resigned as director of Yerkes Observatory and became chairman of the astronomy department at Berkeley
and director of the Leuschner Observatory
. He was succeeded by Kuiper at Yerkes; their relations were strained at times because of Struve's tendencies to keep control of Yerkes management. There were also rumors of similar strains between Struve and Chandrasekhar, but they were always dispersed by the latter, who insisted that Struve always kept scientific relations with his colleagues above the administrative ones. One reason for Struve's move to Berkeley was his tiredness of bureaucracy. In Berkeley, he was spending more time with personal research and students than ever before.
In 1937, Struve discovered a phenomenon which was later named the Struve-Sahade effect
(S-S effect), that is the apparent weakness of lines of the secondary star in massive binary stars when the secondary is receding. This effect poses problems for the accurate reconstruction of the separated primary and secondary spectra. The same year, he discovered interstellar hydrogen in ionized form.
By 1959, Struve has published more than 900 journal articles and books, that places him one of most prolific astronomers (Probably only Ernst Öpik
published more, with 1094 items). Many of those works aimed at popularizing astronomy. In particular, he published 39 articles (and 10 other items) in Popular Astronomy
(1923–1951, the journal was discontinued in 1951), 154 in Sky and Telescope
(1941–1963, the journal was started in 1941) and 83 reviews of books and works by other astronomers. Most of his co-authored scientific articles were co-authored with Pol Swings
and were dedicated to spectroscopical studies of peculiar star
s. To explain his interest in this topic, Struve once noted that he never seen a spectrum of a star where he couldn't find anything to work on.
Struve's major discoveries were detection of stellar rotation and dependence of the
rotational speed on the stellar spectral class (temperature). They spurred the development of
stellar evolution theory. In addition to stellar rotation, he also studied Stark effect
in stellar spectra, that is broadening of the spectral lines by the electric field in the stellar atmosphere. He also worked on the turbulence of stellar atmosphere and expanding shells around stars. This topic required a larger telescope than those available to him. Therefore, between 1933 and 1939, he built a 82-inch telescope at the McDonald Observatory, which was then the second largest telescope in the world (after the Mt. Wilson 100 inches (2.5 m) telescope).
On May 25, 1925, Struve married Mary Martha Lanning, who considered herself a musician but worked as a secretary at Yerkes. Lanning was slightly older than Struve and had been previously married. They had no children; thus the famous Struve astronomical dynasty came to an end. Other branches of the Struve family
besides the line of Otto Wilhelm von Struve
continued, but yielded no distinguished scientists. On October 26, 1927, Struve became a naturalized US citizen. At that time, he was fluent in spoken and written English, but had a slight German accent which remained with him for life. Even after marriage, Struve continued working days and nights, something that his non-scientist wife could not fully accept. Although they remained together, their relations were cold in later years. Struve's health deteriorated in the late 1950s. He was suffering from hepatitis
, first contracted back in Russia and Turkey. In 1956, while using a telescope at Mount Wilson, Struve had a bad fall, breaking several ribs and cracking two vertebrae. He was hospitalized for about two months and had to wear a body cast for a month after recovery. He was permanently hospitalized around 1963 and died on April 6, 1963 in Berkeley. He was survived by his mother and wife. His mother died on October 1, 1964, at the age of ninety. Mary was discovered dead on August 5, 1966, but was estimated to have died in July 1966.
In 1925, Struve met his cousin, the astronomer Georg Hermann Struve
at the Lick Observatory
. In 1930s, they met again at Yerkes Observatory
and reanalyzed observations of the complex multiple star system Zeta Cancri
by their grandfather Otto Wilhelm von Struve
.
Struve was hardly a good teacher: because of his devotion to research and frequent trips, he missed up to two-thirds of his lectures. Nobody was allowed to take his place and students had to do personal research in his absence. Yet, he kept the highest standards of knowledge at the qualifying exams. On the other hand, his infrequent appearances magnetized many students with his passion to astronomy. During his early years at Yerkes, he developed the practice of looking with one eye into the microscope of a micrograph instrument and with another at the nearby numerical table. This probably resulted in his eyes looking into slightly different directions.
Although he did not care much about himself, Struve worried about people. His first paper published in Russian was titled "Aid to Russian Scientists". Civil War brought suffering to most scientific families in Russia. Frost, Struve and George Van Biesbroeck
formed a "Committee for Relief of Russian Astronomers" and organized sending packages of food and clothing. The funds and clothing came from astronomers from all over the US.
During the Great Depression
, he was concerned about hiring foreigners when many Americans were jobless. Around that time, the wife of his deputy George Van Biesbroeck wrote a letter to Belgium, mentioning how Yerkes Observatory was being run by two Europeans. The letter was published and it upset Struve. Eventually, Van Biesbroeck was replaced by American-born W. W. Morgan
.
(1944), the Bruce Medal
(1948), the Henry Draper Medal
of the National Academy of Sciences
(1949) and the Henry Norris Russell Lectureship
of the American Astronomical Society
(1957). His Royal Society medal was the fourth (after Friedrich Georg Wilhelm, Otto Wilhelm and Hermann Struve) and the last received by Struves. The asteroid
768 Struveana
was named in honor of Otto Wilhelm von Struve
, Friedrich Georg Wilhelm Struve and Karl Hermann Struve; and a lunar crater
was named for another 3 astronomers of the Struve family
: Friedrich Georg Wilhelm
, Otto Wilhelm
and Otto. The 82-inch telescope
which Struve used in his research at McDonald Observatory
was named after him in 1966, three year after his death, whereas the asteroid 2227 Otto Struve
kept Struve's name from October 13, 1955.
In 1925, Struve began reviewing articles for the Astrophysical Journal
and from 1932 to 1947, acted as its Editor in Chief. From 1946 till 1949 he was president of American Astronomical Society
. Between 1948 and 1952, he was vice-president and between 1952 and 1955 president of the International Astronomical Union
. In April, 1954 he was elected a Fellow of the Royal Society. Between 1939 and 1961, he received honorary doctorate degrees from nine Universities in Europe and America.
United States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...
. Otto was the descendant of famous astronomers of the Struve family
Struve family
The Struve family were a dynasty of five generations of astronomers from the 18th to 20th centuries. Members of the family were also prominent in chemistry, government and diplomacy.-Origins:...
; he was the son of Ludwig Struve
Ludwig Struve
Gustav Wilhelm Ludwig Struve was a Russian astronomer, part of the famous Baltic German Struve family. In Russian, his name is sometimes given as Lyudvig Ottovich Struve or Lyudvig Ottonovich Struve .-Biography:Gustav Wilhelm Ludwig Struve was born in 1858 in Tsarskoye Selo – a former...
, grandson of Otto Wilhelm von Struve
Otto Wilhelm von Struve
Otto Wilhelm von Struve was a Russian astronomer. In Russian, his name is normally given as Otto Vasil'evich Struve...
and great-grandson of Friedrich Georg Wilhelm von Struve
Friedrich Georg Wilhelm von Struve
Friedrich Georg Wilhelm von Struve was a Danish-Baltic German astronomer from a famous dynasty.-Life:...
. He was also the nephew of Karl Hermann Struve.
With more than 900 journal articles and books, Struve was one of the most distinguished and prolific astronomers of the mid-20th century. He served as director of Yerkes
Yerkes Observatory
Yerkes Observatory is an astronomical observatory operated by the University of Chicago in Williams Bay, Wisconsin. The observatory, which calls itself "the birthplace of modern astrophysics," was founded in 1897 by George Ellery Hale and financed by Charles T. Yerkes...
, McDonald
McDonald Observatory
The McDonald Observatory is an astronomical observatory located near the unincorporated community of Fort Davis in Jeff Davis County, Texas, United States. The facility is located on Mount Fowlkes and Mount Locke in the Davis Mountains of West Texas...
, Leuschner
Leuschner Observatory
Leuschner Observatory, originally called the Students' Observatory, is an observatory operated by the University of California, Berkeley. The observatory was built in 1886 on the Berkeley campus. For many years, it was directed by Armin Otto Leuschner, for whom the observatory was renamed in 1951...
and National Radio Astronomy Observatories
National Radio Astronomy Observatory
The National Radio Astronomy Observatory is a Federally Funded Research and Development Center of the United States National Science Foundation operated under cooperative agreement by Associated Universities, Inc for the purpose of radio astronomy...
and is credited with raising world-wide prestige and building schools of talented scientists at Yerkes and McDonald observatories. In particular, he hired Subrahmanyan Chandrasekhar
Subrahmanyan Chandrasekhar
Subrahmanyan Chandrasekhar, FRS ) was an Indian origin American astrophysicist who, with William A. Fowler, won the 1983 Nobel Prize for Physics for key discoveries that led to the currently accepted theory on the later evolutionary stages of massive stars...
and Gerhard Herzberg
Gerhard Herzberg
Gerhard Heinrich Friedrich Otto Julius Herzberg, was a pioneering physicist and physical chemist, who won the Nobel Prize for Chemistry in 1971, "for his contributions to the knowledge of electronic structure and geometry of molecules, particularly free radicals". Herzberg's main work concerned...
who later became Nobel Prize
Nobel Prize
The Nobel Prizes are annual international awards bestowed by Scandinavian committees in recognition of cultural and scientific advances. The will of the Swedish chemist Alfred Nobel, the inventor of dynamite, established the prizes in 1895...
winners. Struve's research was mostly focused on binary
Binary star
A binary star is a star system consisting of two stars orbiting around their common center of mass. The brighter star is called the primary and the other is its companion star, comes, or secondary...
and variable star
Variable star
A star is classified as variable if its apparent magnitude as seen from Earth changes over time, whether the changes are due to variations in the star's actual luminosity, or to variations in the amount of the star's light that is blocked from reaching Earth...
s, stellar rotation
Stellar rotation
Stellar rotation is the angular motion of a star about its axis. The rate of rotation can be measured from the spectrum of the star, or by timing the movements of active features on the surface....
and interstellar matter. He was one of the few eminent astronomers in the pre-Space Age era to publicly express a belief that extraterrestrial intelligence was abundant, and so was an early advocate of the search for extraterrestrial life.
Early years in Russia
Struve was born in 1897 in KharkivKharkiv
Kharkiv or Kharkov is the second-largest city in Ukraine.The city was founded in 1654 and was a major centre of Ukrainian culture in the Russian Empire. Kharkiv became the first city in Ukraine where the Ukrainian Soviet Socialist Republic was proclaimed in December 1917 and Soviet government was...
, then Russian Empire
Russian Empire
The Russian Empire was a state that existed from 1721 until the Russian Revolution of 1917. It was the successor to the Tsardom of Russia and the predecessor of the Soviet Union...
, as the first child of Ludwig Struve and Elizaveta Khrystoforovna Struve (1874–1964). His astronomy experience started early: from the age of eight, he was accompanying father in the telescope tower and from 10 carried out some minor observations, despite his fear of the dark spaces. After having received home education, at the age of 12, Struve started attending a gymnasium in Kharkiv and showed mathematical talents. Otto was the first child of the Struve family in Russia who attended a Russian-speaking rather than German-speaking school, and was bilingual in German and Russian. After graduating in 1914, he continued his astronomy work. In June 1914, Struve took part in preparations for observation of a total solar eclipse (August 8, 1914) and later used that experience and results for his masters degree work defended in 1919 at Kharkiv University.
Struve entered the Kharkiv University in 1915, at the time of political unrest and wars in Russia. In the beginning of 1916, just having finished the first semester, he interrupted his studies and enlisted to a military artillery school in St. Petersburg. He passed an accelerated training program, and in February 1917, was sent to the Turkish front. After the Treaty of Brest-Litovsk
Treaty of Brest-Litovsk
The Treaty of Brest-Litovsk was a peace treaty signed on March 3, 1918, mediated by South African Andrik Fuller, at Brest-Litovsk between Russia and the Central Powers, headed by Germany, marking Russia's exit from World War I.While the treaty was practically obsolete before the end of the year,...
was signed, Struve returned to Kharkiv for a year between spring 1918 and spring 1919 and completed a full university course. in June 1919, he received a certificate signed by the rector of Kharkiv University stating that Struve will stay with the University to prepare for professorship at the department of astronomy and geodesics. During that time, Struve also worked at the "workshop school of fine mechanics" and obtained a license of a workshop trainer. The workshop was organized by his father with the goal of creating traditions of astronomy engineers in Russia. Those were non-existent and foreign engineers were personally invited from abroad for high-quality mechanical work.
Moving to the US
The German origin of Struves and the military history of Otto Struve with the White Russian ArmyWhite movement
The White movement and its military arm the White Army - known as the White Guard or the Whites - was a loose confederation of Anti-Communist forces.The movement comprised one of the politico-military Russian forces who fought...
took its toll. To avoid repressions of the Bolsheviks, his family had to move from Kharkiv to Sevastopol
Sevastopol
Sevastopol is a city on rights of administrative division of Ukraine, located on the Black Sea coast of the Crimea peninsula. It has a population of 342,451 . Sevastopol is the second largest port in Ukraine, after the Port of Odessa....
which was still under control of the White Army. There, a series of tragedies took away most of the family: the youngest sister Elizabeth drowned, brother Werner died from tuberculosis
Tuberculosis
Tuberculosis, MTB, or TB is a common, and in many cases lethal, infectious disease caused by various strains of mycobacteria, usually Mycobacterium tuberculosis. Tuberculosis usually attacks the lungs but can also affect other parts of the body...
, and father was taken by a stroke on November 4, 1920. Whereas his mother and sister returned to Kharkiv, on November 16–17, 1920, Otto followed the escaping Wrangel's Army
Russian Civil War
The Russian Civil War was a multi-party war that occurred within the former Russian Empire after the Russian provisional government collapsed to the Soviets, under the domination of the Bolshevik party. Soviet forces first assumed power in Petrograd The Russian Civil War (1917–1923) was a...
. With a military transport, he escaped from Sevastopol to Turkey and never returned to Russia since then. He was later invited several times to conferences in the Soviet Union, but for various reasons declined to attend.
During the year and a half that Otto spent in exile in Gallipoli
Gallipoli
The Gallipoli peninsula is located in Turkish Thrace , the European part of Turkey, with the Aegean Sea to the west and the Dardanelles straits to the east. Gallipoli derives its name from the Greek "Καλλίπολις" , meaning "Beautiful City"...
and later in Constantinople
Constantinople
Constantinople was the capital of the Roman, Eastern Roman, Byzantine, Latin, and Ottoman Empires. Throughout most of the Middle Ages, Constantinople was Europe's largest and wealthiest city.-Names:...
, he became an impoverished refugee, eating at relief agencies and taking any job he could find. For some time, he worked as a woodcutter, sleeping with fellow Russian officers, 6 people in a tent. One night, a neighboring tent was hit by lightning, killing everyone inside. Struve wrote to his uncle Hermann Struve
Hermann Struve
Karl Hermann Struve was a Russian astronomer. In Russian, his name is sometimes given as German Ottovich Struve or German Ottonovich Struve ....
in Germany for assistance, without knowing that the latter had died a few months earlier, on August 12, 1920. However, the widow of Hermann, Eva Struve, contacted Paul Guthnick, her late husband's successor at the Berlin-Babelsberg Observatory
Berlin Observatory
The Berlin Observatory is a series of observatories and related organizations in and around the city of Berlin in Germany, starting from the 18th century...
. Germany itself was suffering after the wars, and there was little chance to obtain a position for a Russian there. Therefore, Guthnick wrote, on December 25, 1920, to the director of Yerkes Observatory
Yerkes Observatory
Yerkes Observatory is an astronomical observatory operated by the University of Chicago in Williams Bay, Wisconsin. The observatory, which calls itself "the birthplace of modern astrophysics," was founded in 1897 by George Ellery Hale and financed by Charles T. Yerkes...
in Chicago
Chicago
Chicago is the largest city in the US state of Illinois. With nearly 2.7 million residents, it is the most populous city in the Midwestern United States and the third most populous in the US, after New York City and Los Angeles...
Edwin B. Frost asking position for Struve. He received a reply on January 27, 1921, where Frost promised to do his best. On March 2, 1921, Frost wrote to Struve, offering him a position at Yerkes. Given his situation in Turkey, it was a lucky chance that Struve received that letter. On March 11, Struve sent a reply, thanking for the offer and accepting it. The letter was formally written in English but with German grammar, revealing the poor English proficiency of Struve (When they later met in US, they spoke in German). Struve also acknowledged that he had no experience in spectral astrophysics. Nevertheless, when applying for his position, Frost mentioned that "I am perfectly willing to take him on his lineage .. We regard Otto Struve as first-class spectroscopist and astrophysicist " and that his degree in Kharkiv was equivalent to a doctor degree (which Struve never claimed and which was hardly so). It took several months to arrange for travel documents and funding. In late August 1921, Struve received his visa and travel tickets at the US Consulate in Turkey. In September, he boarded S.S. Hog Island and on October 7, 1921, arrived in New York. He was met there, put on the train, and 2 days later arrived in Chicago.
Life in the US
In late 1921, Struve began working as a stellar spectroscopy assistant at Yerkes with a monthly salary of $75, starting with taking a training course. The observatory was in decline and Struve was alone in class. Three more students joined him in 1922, but only for a summer, and only one of those continued later. There was no lectures, and the students were learning by reading, practice and discussions with professors.Struve proved to be a quick learner and talented scientist. Five months after arrival, he made his first discovery of a pulsating star at Gamma Ursae Minoris
Gamma Ursae Minoris
Gamma Ursae Minoris is a slightly variable star in the constellation Ursa Minor. It also has the common name Pherkad. Together with Beta Ursae Minoris, Gamma forms the end of the dipper pan of the "Little Dipper"...
and wrote an article on it in September 1922. He was spending more time with observations than anyone at Yerkes, trying every telescope available there, also making weather observations at Williams Bay
Williams Bay, Wisconsin
Williams Bay is a village in Walworth County, Wisconsin, United States. The population was 2,415 at the 2000 census.-Geography:Williams Bay is located at ....
. On October 24, 1922, he discovered the asteroid
Asteroid
Asteroids are a class of small Solar System bodies in orbit around the Sun. They have also been called planetoids, especially the larger ones...
991 McDonalda
991 McDonalda
991 McDonalda is a Themistian asteroid. It was discovered by Otto Struve in 1922 at the Yerkes Observatory in Williams Bay, Wisconsin, USA. It is named after the McDonald Observatory, which Struve helped found in 1939.-External links:*...
and on November 14 of the same year, another asteroid 992 Swasey
992 Swasey
992 Swasey is an asteroid, a minor planet orbiting the Sun. It was discovered by Otto Struve in 1922 at the Yerkes Observatory in Williams Bay, Wisconsin, USA. It is named after Ambrose Swasey of the Warner & Swasey Company, which built the 82-inch telescope named after Struve at McDonald...
.
As early as December 1923, Struve defended his PhD thesis on short-period spectroscopic double star
Double star
In observational astronomy, a double star is a pair of stars that appear close to each other in the sky as seen from Earth when viewed through an optical telescope. This can happen either because the pair forms a binary star, i.e...
s at the University of Chicago
University of Chicago
The University of Chicago is a private research university in Chicago, Illinois, USA. It was founded by the American Baptist Education Society with a donation from oil magnate and philanthropist John D. Rockefeller and incorporated in 1890...
. Frost helped him in waiving some required PhD examinations, e.g. in French and German, stating that Struve had done ample reading of scientific literature back in Russia, and was fluent in those languages. Struve then became an instructor (January 1924), assistant professor (1927) and full professor (1932) at the university. His rapid promotion was again assisted by Frost, who also used job-offer letters from other observatories to Struve as proof that Struve was a highly valued scientist who must be kept at Chicago University. Between 1932 and 1947, Struve headed Yerkes Observatory; from 1939 to 1950 he acted as a founding director of the McDonald Observatory
McDonald Observatory
The McDonald Observatory is an astronomical observatory located near the unincorporated community of Fort Davis in Jeff Davis County, Texas, United States. The facility is located on Mount Fowlkes and Mount Locke in the Davis Mountains of West Texas...
, and from July 1, 1952 to 1962 served as the first director of the National Radio Astronomy Observatory
National Radio Astronomy Observatory
The National Radio Astronomy Observatory is a Federally Funded Research and Development Center of the United States National Science Foundation operated under cooperative agreement by Associated Universities, Inc for the purpose of radio astronomy...
at University of Virginia
University of Virginia
The University of Virginia is a public research university located in Charlottesville, Virginia, United States, founded by Thomas Jefferson...
. All those years, he remained in America except for conferences and an 8-month sabbatical leave to Cambridge University between August 1928 and May 1929. He applied for and won a Guggenheim Fellowship
Guggenheim Fellowship
Guggenheim Fellowships are American grants that have been awarded annually since 1925 by the John Simon Guggenheim Memorial Foundation to those "who have demonstrated exceptional capacity for productive scholarship or exceptional creative ability in the arts." Each year, the foundation makes...
to cover his travel to, and living expenses in, Cambridge. While in Cambridge, Struve mostly worked on interstellar matter; he also went on a short trip to Leiden to meet Jan Oort
Jan Oort
Jan Hendrik Oort was a Dutch astronomer. He was a pioneer in the field of radio astronomy. The Oort cloud of comets bears his name....
.
Struve was a highly successful administrator who brought fame to Yerks Observatory and rebuilt the astronomy department of the University of Chicago. In particular, he gradually renewed the scientific staff, dismissing stagnated permanent researchers who were not making significant contributions to science but were occupying the faculty positions. The process was difficult. Struve used to arrive first and leave last from the observatory, taking notes on working hours of staff which he then used in his bureaucratic moves. In replacement, he hired several young and talented researchers who later became world-famous scientists. Those included Subrahmanyan Chandrasekhar
Subrahmanyan Chandrasekhar
Subrahmanyan Chandrasekhar, FRS ) was an Indian origin American astrophysicist who, with William A. Fowler, won the 1983 Nobel Prize for Physics for key discoveries that led to the currently accepted theory on the later evolutionary stages of massive stars...
(Nobel Prize in Physics
Nobel Prize in Physics
The Nobel Prize in Physics is awarded once a year by the Royal Swedish Academy of Sciences. It is one of the five Nobel Prizes established by the will of Alfred Nobel in 1895 and awarded since 1901; the others are the Nobel Prize in Chemistry, Nobel Prize in Literature, Nobel Peace Prize, and...
in 1983), Gerard Kuiper
Gerard Kuiper
Gerard Peter Kuiper , Netherlands – December 24, 1973, Mexico City) was a Dutch-American astronomer after whom the Kuiper belt was named.-Early life:...
(protagonist of the famous Kuiper Prize), Bengt Strömgren
Bengt Strömgren
Bengt Georg Daniel Strömgren was a Danish astronomer and astrophysicist.Bengt Strömgren was born in Gothenburg. His parents were Hedvig Strömgren and Svante Elis Strömgren, who was professor of astronomy at the University of Copenhagen and director of the University Observatory in Copenhagen...
, Gerhard Herzberg
Gerhard Herzberg
Gerhard Heinrich Friedrich Otto Julius Herzberg, was a pioneering physicist and physical chemist, who won the Nobel Prize for Chemistry in 1971, "for his contributions to the knowledge of electronic structure and geometry of molecules, particularly free radicals". Herzberg's main work concerned...
(Nobel Prize in Chemistry
Nobel Prize in Chemistry
The Nobel Prize in Chemistry is awarded annually by the Royal Swedish Academy of Sciences to scientists in the various fields of chemistry. It is one of the five Nobel Prizes established by the will of Alfred Nobel in 1895, awarded for outstanding contributions in chemistry, physics, literature,...
in 1971), William Wilson Morgan
William Wilson Morgan
William Wilson Morgan was an American astronomer.The principal theme in Morgan's work was the study of stellar and galaxy classification. Along...
and Jesse L. Greenstein
Jesse L. Greenstein
Jesse Leonard Greenstein was an American astronomer. His parents were Maurice G. and Leah Feingold....
. After World War II, he also invited a number of leading European researchers, such as Pol Swings
Pol Swings
Pol F. Swings was a Belgian astrophysicist who was known for his studies of the composition and structure of stars and comets. He used spectroscopy to identify the elements in astronomical bodies, and, in particular, comets...
, Jan Oort
Jan Oort
Jan Hendrik Oort was a Dutch astronomer. He was a pioneer in the field of radio astronomy. The Oort cloud of comets bears his name....
(father of radio astronomy
Radio astronomy
Radio astronomy is a subfield of astronomy that studies celestial objects at radio frequencies. The initial detection of radio waves from an astronomical object was made in the 1930s, when Karl Jansky observed radiation coming from the Milky Way. Subsequent observations have identified a number of...
), Marcel Minnaert
Marcel Minnaert
Marcel Gilles Jozef Minnaert was a Belgian astronomer.He obtained a PhD in biology at Ghent University in 1914....
, H. C. van der Hulst and Albrecht Unsöld
Albrecht Unsöld
Albrecht Otto Johannes Unsöld was a German astrophysicist known for his contributions to spectroscopic analysis of stellar atmospheres.-Career:...
. As most of them were foreigners, their appointment met strong opposition from the science officials for various reasons, such as taking jobs from Americans during the Great Depression
Great Depression
The Great Depression was a severe worldwide economic depression in the decade preceding World War II. The timing of the Great Depression varied across nations, but in most countries it started in about 1929 and lasted until the late 1930s or early 1940s...
. India-born Chandrasekhar, who stayed in the Soviet Union, was also suspected of Communist connections. Struve spent extraordinary efforts defending and justifying each case, and those efforts paid off in building the scientific school at Yerkes and Chicago University. For example, Chandrasekhar spent his entire career as a scientist and administrator at Chicago University, assisting Struve and eventually replacing him as president of the American Astronomical Society
American Astronomical Society
The American Astronomical Society is an American society of professional astronomers and other interested individuals, headquartered in Washington, DC...
(from 1949) and as the Editor in Chief of the Astrophysical Journal
Astrophysical Journal
The Astrophysical Journal is a peer-reviewed scientific journal covering astronomy and astrophysics. It was founded in 1895 by the American astronomers George Ellery Hale and James Edward Keeler. It publishes three 500-page issues per month....
.
By the late 1940s, many young researchers whom Struve invited to Yerkes became established scientists. This created friction, as they did not want to follow his every word and were building their own careers. In 1947, Struve resigned as director of Yerkes Observatory and became chairman of the astronomy department at Berkeley
University of California, Berkeley
The University of California, Berkeley , is a teaching and research university established in 1868 and located in Berkeley, California, USA...
and director of the Leuschner Observatory
Leuschner Observatory
Leuschner Observatory, originally called the Students' Observatory, is an observatory operated by the University of California, Berkeley. The observatory was built in 1886 on the Berkeley campus. For many years, it was directed by Armin Otto Leuschner, for whom the observatory was renamed in 1951...
. He was succeeded by Kuiper at Yerkes; their relations were strained at times because of Struve's tendencies to keep control of Yerkes management. There were also rumors of similar strains between Struve and Chandrasekhar, but they were always dispersed by the latter, who insisted that Struve always kept scientific relations with his colleagues above the administrative ones. One reason for Struve's move to Berkeley was his tiredness of bureaucracy. In Berkeley, he was spending more time with personal research and students than ever before.
Research
Struve-Sahade effect
The Struve-Sahade effect occurs with a double-lined spectroscopic binary star system. A spectroscopic binary is called double-lined when the absorption lines of both stars can be observed with a spectroscope...
(S-S effect), that is the apparent weakness of lines of the secondary star in massive binary stars when the secondary is receding. This effect poses problems for the accurate reconstruction of the separated primary and secondary spectra. The same year, he discovered interstellar hydrogen in ionized form.
By 1959, Struve has published more than 900 journal articles and books, that places him one of most prolific astronomers (Probably only Ernst Öpik
Ernst Öpik
Ernst Julius Öpik was a noted Estonian astronomer and astrophysicist who spent the second half of his career at the Armagh Observatory in Northern Ireland.-Education:...
published more, with 1094 items). Many of those works aimed at popularizing astronomy. In particular, he published 39 articles (and 10 other items) in Popular Astronomy
Popular Astronomy (US magazine)
Popular Astronomy was a magazine for amateur astronomers published between 1893 and 1951. It was the successor to The Sidereal Messenger, which ceased publication in 1892. Each yearly volume of Popular Astronomy contained 10 issues, for a total of 59 volumes.The first editor, from 1893-1911, was...
(1923–1951, the journal was discontinued in 1951), 154 in Sky and Telescope
Sky & Telescope
Sky & Telescope is a monthly American magazine covering all aspects of amateur astronomy, including the following:*current events in astronomy and space exploration;*events in the amateur astronomy community;...
(1941–1963, the journal was started in 1941) and 83 reviews of books and works by other astronomers. Most of his co-authored scientific articles were co-authored with Pol Swings
Pol Swings
Pol F. Swings was a Belgian astrophysicist who was known for his studies of the composition and structure of stars and comets. He used spectroscopy to identify the elements in astronomical bodies, and, in particular, comets...
and were dedicated to spectroscopical studies of peculiar star
Peculiar star
In astrophysics, peculiar stars have distinctly unusual metal abundances, at least in their surface layers.Chemically peculiar stars are common among hot main sequence stars...
s. To explain his interest in this topic, Struve once noted that he never seen a spectrum of a star where he couldn't find anything to work on.
Struve's major discoveries were detection of stellar rotation and dependence of the
rotational speed on the stellar spectral class (temperature). They spurred the development of
stellar evolution theory. In addition to stellar rotation, he also studied Stark effect
Stark effect
The Stark effect is the shifting and splitting of spectral lines of atoms and molecules due to presence of an external static electric field. The amount of splitting and or shifting is called the Stark splitting or Stark shift. In general one distinguishes first- and second-order Stark effects...
in stellar spectra, that is broadening of the spectral lines by the electric field in the stellar atmosphere. He also worked on the turbulence of stellar atmosphere and expanding shells around stars. This topic required a larger telescope than those available to him. Therefore, between 1933 and 1939, he built a 82-inch telescope at the McDonald Observatory, which was then the second largest telescope in the world (after the Mt. Wilson 100 inches (2.5 m) telescope).
Views on extraterrestrial life
Struve's belief in the widespread existence of life and intelligence in the Universe stemmed from his studies of slow-rotating stars. Many stars, including the Sun, spin at a much lower rate than was predicted by contemporary theories of early stellar evolution. The reason for this, claimed Struve, was that they were surrounded by planetary systems which had carried away much of the stars' original angular momentum. So numerous were the slow-spinning stars that Struve estimated, in 1960, there might be as many as 50 billion planets in our Galaxy alone. As to how many might harbor intelligent life, he wrote:- "An intrinsically improbable event may become highly probable if the number of events is very great. ... [I]t is probable that a good many of the billions of planets in the Milky Way support intelligent forms of life. To me this conclusion is of great philosophical interest. I believe that science has reached the point where it is necessary to take into account the action of intelligent beings, in addition to the classical laws of physics."
Personal life, family relations and late years
Struve had a younger brother and two sisters, all of whom died in Russia in their youth: Werner (1903–1920), Yadviga (1901–1924) and Elizabeth (1911–1920). The last death in 1924 left his mother with no close relatives in Russia. After Struve arranged visa documents, she immigrated to the US in January 1925. Remarkably, his mother began working in astronomy in the US and assisted in processing of the measurements. She lived with Struve even after his marriage.On May 25, 1925, Struve married Mary Martha Lanning, who considered herself a musician but worked as a secretary at Yerkes. Lanning was slightly older than Struve and had been previously married. They had no children; thus the famous Struve astronomical dynasty came to an end. Other branches of the Struve family
Struve family
The Struve family were a dynasty of five generations of astronomers from the 18th to 20th centuries. Members of the family were also prominent in chemistry, government and diplomacy.-Origins:...
besides the line of Otto Wilhelm von Struve
Otto Wilhelm von Struve
Otto Wilhelm von Struve was a Russian astronomer. In Russian, his name is normally given as Otto Vasil'evich Struve...
continued, but yielded no distinguished scientists. On October 26, 1927, Struve became a naturalized US citizen. At that time, he was fluent in spoken and written English, but had a slight German accent which remained with him for life. Even after marriage, Struve continued working days and nights, something that his non-scientist wife could not fully accept. Although they remained together, their relations were cold in later years. Struve's health deteriorated in the late 1950s. He was suffering from hepatitis
Hepatitis
Hepatitis is a medical condition defined by the inflammation of the liver and characterized by the presence of inflammatory cells in the tissue of the organ. The name is from the Greek hepar , the root being hepat- , meaning liver, and suffix -itis, meaning "inflammation"...
, first contracted back in Russia and Turkey. In 1956, while using a telescope at Mount Wilson, Struve had a bad fall, breaking several ribs and cracking two vertebrae. He was hospitalized for about two months and had to wear a body cast for a month after recovery. He was permanently hospitalized around 1963 and died on April 6, 1963 in Berkeley. He was survived by his mother and wife. His mother died on October 1, 1964, at the age of ninety. Mary was discovered dead on August 5, 1966, but was estimated to have died in July 1966.
In 1925, Struve met his cousin, the astronomer Georg Hermann Struve
Georg Hermann Struve
Georg Otto Hermann Struve was a German astronomer from the Struve family and the son of Hermann Struve.Georg was born in 1886 in Tsarskoye Selo – a former Russian residence of the imperial family and visiting nobility, located south from the center of St. Petersburg. In 1895, his family...
at the Lick Observatory
Lick Observatory
The Lick Observatory is an astronomical observatory, owned and operated by the University of California. It is situated on the summit of Mount Hamilton, in the Diablo Range just east of San Jose, California, USA...
. In 1930s, they met again at Yerkes Observatory
Yerkes Observatory
Yerkes Observatory is an astronomical observatory operated by the University of Chicago in Williams Bay, Wisconsin. The observatory, which calls itself "the birthplace of modern astrophysics," was founded in 1897 by George Ellery Hale and financed by Charles T. Yerkes...
and reanalyzed observations of the complex multiple star system Zeta Cancri
Zeta Cancri
Zeta Cancri is a star system in the constellation Cancer containing at least four stars. It has the traditional name Tegmine "the shell "...
by their grandfather Otto Wilhelm von Struve
Otto Wilhelm von Struve
Otto Wilhelm von Struve was a Russian astronomer. In Russian, his name is normally given as Otto Vasil'evich Struve...
.
Personal qualities
Struve was often described as a big and intimidating man. According to him, in his fifties, he was six feet tall, weighed 192 pounds, had gray hair and eyes. Struve was also known as persistent, dedicated and demanding, both to himself and others – the qualities preserved in his family for generations. He was first to arrive at the observatory, often working until late evening in the office, and then spending nights with a telescope. "He had only one interest and concern, namely, that astronomy should be developed and pushed to the maximum that was possible". As a result, Struve was usually overworked, developed an insomnia and often appeared as in a daze after a 2-3 hour sleep.Struve was hardly a good teacher: because of his devotion to research and frequent trips, he missed up to two-thirds of his lectures. Nobody was allowed to take his place and students had to do personal research in his absence. Yet, he kept the highest standards of knowledge at the qualifying exams. On the other hand, his infrequent appearances magnetized many students with his passion to astronomy. During his early years at Yerkes, he developed the practice of looking with one eye into the microscope of a micrograph instrument and with another at the nearby numerical table. This probably resulted in his eyes looking into slightly different directions.
Although he did not care much about himself, Struve worried about people. His first paper published in Russian was titled "Aid to Russian Scientists". Civil War brought suffering to most scientific families in Russia. Frost, Struve and George Van Biesbroeck
George Van Biesbroeck
George A. Van Biesbroeck was a Belgian-American astronomer. He worked at observatories in Belgium, Germany and the United States. He specialized in the observation of double stars, asteroids and comets...
formed a "Committee for Relief of Russian Astronomers" and organized sending packages of food and clothing. The funds and clothing came from astronomers from all over the US.
During the Great Depression
Great Depression
The Great Depression was a severe worldwide economic depression in the decade preceding World War II. The timing of the Great Depression varied across nations, but in most countries it started in about 1929 and lasted until the late 1930s or early 1940s...
, he was concerned about hiring foreigners when many Americans were jobless. Around that time, the wife of his deputy George Van Biesbroeck wrote a letter to Belgium, mentioning how Yerkes Observatory was being run by two Europeans. The letter was published and it upset Struve. Eventually, Van Biesbroeck was replaced by American-born W. W. Morgan
William Wilson Morgan
William Wilson Morgan was an American astronomer.The principal theme in Morgan's work was the study of stellar and galaxy classification. Along...
.
Awards and honors
Struve received the Gold Medal of the Royal Astronomical SocietyGold Medal of the Royal Astronomical Society
-History:In the early years, more than one medal was often awarded in a year, but by 1833 only one medal was being awarded per year. This caused a problem when Neptune was discovered in 1846, because many felt an award should jointly be made to John Couch Adams and Urbain Le Verrier...
(1944), the Bruce Medal
Bruce Medal
The Catherine Wolfe Bruce Gold Medal is awarded every year by the Astronomical Society of the Pacific for outstanding lifetime contributions to astronomy. It is named after Catherine Wolfe Bruce, an American patroness of astronomy, and was first awarded in 1898...
(1948), the Henry Draper Medal
Henry Draper Medal
The Henry Draper Medal is awarded by the United States National Academy of Sciences "for investigations in astronomical physics". Named after Henry Draper, the medal is awarded with a gift of USD $15,000...
of the National Academy of Sciences
United States National Academy of Sciences
The National Academy of Sciences is a corporation in the United States whose members serve pro bono as "advisers to the nation on science, engineering, and medicine." As a national academy, new members of the organization are elected annually by current members, based on their distinguished and...
(1949) and the Henry Norris Russell Lectureship
Henry Norris Russell Lectureship
The Henry Norris Russell Lectureship is awarded each year by the American Astronomical Society in recognition of a lifetime of excellence in astronomical research.-Previous lecturers:This list of lecturers is from the American Astronomical Society's website....
of the American Astronomical Society
American Astronomical Society
The American Astronomical Society is an American society of professional astronomers and other interested individuals, headquartered in Washington, DC...
(1957). His Royal Society medal was the fourth (after Friedrich Georg Wilhelm, Otto Wilhelm and Hermann Struve) and the last received by Struves. The asteroid
Asteroid
Asteroids are a class of small Solar System bodies in orbit around the Sun. They have also been called planetoids, especially the larger ones...
768 Struveana
768 Struveana
768 Struveana is a minor planet orbiting the Sun. The asteroid was named jointly in honor of Friedrich Georg Wilhelm von Struve, Otto Wilhelm von Struve and Karl Hermann Struve.-External links:*...
was named in honor of Otto Wilhelm von Struve
Otto Wilhelm von Struve
Otto Wilhelm von Struve was a Russian astronomer. In Russian, his name is normally given as Otto Vasil'evich Struve...
, Friedrich Georg Wilhelm Struve and Karl Hermann Struve; and a lunar crater
Struve (crater)
Struve is the lava-flooded remains of a lunar impact crater. It is located near the western extreme of the Oceanus Procellarum, close to the western lunar limb...
was named for another 3 astronomers of the Struve family
Struve family
The Struve family were a dynasty of five generations of astronomers from the 18th to 20th centuries. Members of the family were also prominent in chemistry, government and diplomacy.-Origins:...
: Friedrich Georg Wilhelm
Friedrich Georg Wilhelm von Struve
Friedrich Georg Wilhelm von Struve was a Danish-Baltic German astronomer from a famous dynasty.-Life:...
, Otto Wilhelm
Otto Wilhelm von Struve
Otto Wilhelm von Struve was a Russian astronomer. In Russian, his name is normally given as Otto Vasil'evich Struve...
and Otto. The 82-inch telescope
Otto Struve Telescope
The Otto Struve Telescope was the first major telescope to be built at McDonald Observatory. Located in the Davis Mountains in West Texas, the Otto Struve Telescope was designed by Warner & Swasey Company and constructed between 1933 and 1939 by the Paterson-Leitch Company. Its 2.1 meter mirror...
which Struve used in his research at McDonald Observatory
McDonald Observatory
The McDonald Observatory is an astronomical observatory located near the unincorporated community of Fort Davis in Jeff Davis County, Texas, United States. The facility is located on Mount Fowlkes and Mount Locke in the Davis Mountains of West Texas...
was named after him in 1966, three year after his death, whereas the asteroid 2227 Otto Struve
2227 Otto Struve
2227 Otto Struve is the name of an asteroid which was discovered at Goethe Link Observatory near Brooklyn, Indiana by the Indiana Asteroid Program. It is named for the astronomer Otto Struve , who discovered two asteroids himself ....
kept Struve's name from October 13, 1955.
In 1925, Struve began reviewing articles for the Astrophysical Journal
Astrophysical Journal
The Astrophysical Journal is a peer-reviewed scientific journal covering astronomy and astrophysics. It was founded in 1895 by the American astronomers George Ellery Hale and James Edward Keeler. It publishes three 500-page issues per month....
and from 1932 to 1947, acted as its Editor in Chief. From 1946 till 1949 he was president of American Astronomical Society
American Astronomical Society
The American Astronomical Society is an American society of professional astronomers and other interested individuals, headquartered in Washington, DC...
. Between 1948 and 1952, he was vice-president and between 1952 and 1955 president of the International Astronomical Union
International Astronomical Union
The International Astronomical Union IAU is a collection of professional astronomers, at the Ph.D. level and beyond, active in professional research and education in astronomy...
. In April, 1954 he was elected a Fellow of the Royal Society. Between 1939 and 1961, he received honorary doctorate degrees from nine Universities in Europe and America.
External links
- Guide to the Otto Struve Papers at The Bancroft Library