Dubyago, Alexander Dmitrievich

Born December 18, 1903 in Kazan in the family of the famous Russian astronomer, rector of Kazan University , Dmitry Ivanovich Dubyago . In the summer, the Dubyago family went to the forest Engelhardt Observatory ; it is not surprising, therefore, that Alexander Dmitrievich Dubyago became interested in astronomy early on; when he was 11 years old, his father began to take him with him for observation, at the age of 12-13 he was already studying variable stars on his own, and at 14 he was one of the first to notice a new star in the constellation Oryol - he was elected a member of the Russian Astronomical society and awarded the gold medal to them. Golubeva.

At the end of 1918 - after the death of his father, at the age of 15 he was enrolled in the staff of the astronomical observatory of Kazan University as a computer, whose responsibilities included determining the exact time corrections from astronomical observations. In 1919, the Russian Society of lovers of world studies elected him an associate member, and a year later - a corresponding member. At the same time, he began to seriously engage in music with a famous teacher in Kazan, V. M. Kunavina.

Student years

In 1920, Alexander Dmitrievich Dubyago, having passed exams for the gymnasium course as an external student, entered the Physics and Mathematics Department of Kazan University , while continuing to work as a computer in the department of astronomy.

Being a skilled observer, Dubyago discovered two comets . The first of them was opened on April 24, 1921 and received the name 1921 I (according to the modern nomenclature C / 1921 H1 (Dubiago) ). Subsequently, after the publication of observations of this comet, Dubyago calculated its elliptical orbit, which turned out to be a member of the Neptune family with a circulation period of 79.5 years. The second comet - 1923 III (Bernard - Dubiago) - he discovered on October 14, 1923 .

In 1923, A.D. Dubyago published his first work on the study of the movement of comets. One of them contained a prediction of the appearance of comet d'Arre (6P / d'Arrest) in 1923, and in 1920 this comet had close proximity to Jupiter , which greatly complicated the calculation of its parameters. His other student work was devoted to determining the final orbit of comet 1909 IV (Daniel) . In this large-scale work, A.D. Dubyago proved himself to be a subtle and demanding researcher. He re-reduced all 188 comparison stars using inaccessible star catalogs , brought the position of these stars to the Boss Fundamental System, and simultaneously determined the proper motions of 23 stars. Based on the final elements of the orbit of comet 1909 IV, A. D. Dubyago re-calculated its ephemeris taking into account disturbances from Jupiter for 1916 and showed that the comet was not found that year due to incorrect calculations, and not due to poor conditions her appearances, as was then supposed. In his student years, he completed the first of the works related to Brooks' comet - this comet became the "companion" of Alexander Dmitrievich throughout his entire scientific career.

Scientific work

After graduating from Kazan University in February 1925, A.D. Dubyago was left an assistant at the Department of Astronomy and spent his entire future life in the walls of his native university, going from a computer to a professor and a world-famous scientist.

In 1925, Dubiago took up the difficult task of predicting the appearance of "Brooks Comet." The study of the comet’s orbit was first begun by Bausinger , but his work remained unfinished. In 1928, Dubyago turned to Bausinger with a request to inform him of some unpublished material relating to Comet Brooks. In a letter dated November 17, 1928, Bausinger said that he had already suspected Century Acceleration of comet Brooks in 1911 , and expressed the hope that the work he began would be completed. However, Dubyago, taking up the study of the motion of Comet Brooks, posed a deeper task - not only to establish secular acceleration, but also to find out the reasons that cause it. He thoroughly revised all observations of the comet during its appearance in 1889-1891, 1896-1897 and 1903-1904, as well as the only observation in 1910. As a result, he concluded that some force, not yet known, acts on the comet, he argued that this force changes any element of the orbit, just as disturbances from large planets change all elements of elliptical motion. Dubyago, having studied the movement of Comet Brooks, first in 63 years, from 1883 to 1946, and then another 35 years from 1925 to 1960, proved that in the movement of short-period comets deviations from the gravitational theory are not an exception, but a rule; he showed that due to the loss of matter by the comet near the Sun, a change in all elements of the orbit of the nucleus occurs. After making an approximate estimate of the mass loss by the nuclei of comets (about 2% of the total mass of the nucleus), he concluded that not only gases, but also solid particles are ejected from the comet. Kazan University praised the work of A. D. Dubyago, “Investigation of the Movement of Comet Brooks in 1925-1940,” awarding the author a second prize in the competition of the best scientific works of university scientists in 1944.

A.D. Dubyago was not a supporter of S.K. Vsekhsvyatsky ’s hypothesis about the origin of comets, since he believed that there cannot and should not be two theories of the origin of comets, one for short-period comets and the other for comets with orbits close to a parabola . He was not a supporter of the opinion about the genetic connection between comets and asteroids . He saw a significant difference between them not only in the fact that short-period comets, as a rule, come close to Jupiter and are strongly disturbed, but primarily because comets in many cases are physically connected with meteor showers . It follows that the nuclei of comets cannot be monolithic bodies, like asteroids. A.D. Dubyago believed that the formation of comets from the dust medium that fills the solar system seems most likely. In 1942, he proposed a mechanism for the formation of seals in a dusty environment: individual swarms of particles moving around the Sun can, when approaching a planet, for example, Jupiter, experience very strong disturbances, due to which the swarm can be thrown to the periphery of the solar system and remain there for a long time sufficient to seal it; since the compaction process will proceed slowly at the initial stage, this may cause ice enveloping of individual small bodies due to the condensation of gases of the interstellar medium; nuclei will become conglomerates of solids and ice .; then such a condensed swarm will return to the Sun, and will be observed as a comet. Depending on the initial distance over which the swarm was thrown, the fate of the comet should also be formed, that is, whether it will be short-period or long-period.

A little later, when studying the motion of the periodic comet 61P / Shine-Shaldek, Dubiago put forward a hypothesis according to which short-period comets are formed in the zone of motion of Jupiter. As a result of several convergence of the comet with Jupiter, the initial shape of the orbit changes, the perihelion distance becomes quite small and the comet becomes observable. The orbit of “comet P. F. Shine-Shaldek” served as an example of the transition from a circular orbit to an elliptical short-period orbit after only one approach to Jupiter.

Based on his theory of the formation of cometary nuclei, A.D. Dubyago explained the origin of meteor showers associated with periodic comets, determining the propagation velocity of meteor showers along the orbits of the parent comets.

Alexander Dmitrievich Dubyago was a computer virtuoso. He calculated the parabolic or elliptical orbit from three observations within 2-3 hours (in the era of the absence of computers). From the moment D. Y. Martynov organized the Astronomical Circular in Kazan, Dubyago calculated the first elements and search ephemeris for almost all newly discovered comets. Alexander Dmitrievich outlined his rich experience in celestial-mechanical calculations in the monograph Definition of Orbits (M., 1949) - it was translated and published in the USA after the death of the author.

From 1918 to 1930, Dubyago conducted visual observations of variables at the Kazan Observatory; He participated in the first conference of variable star researchers in Nizhny Novgorod . From his observations, A.D. Dubyago obtained and published new elements of brightness change (“XZ Reg”, “AO Peg”, “WY And”, etc.). Extensive computations for processing the observations of both our own and other authors were required by the joint work of A.D. Dubyago and D. Ya. Martynov on the analysis of the eclipsing variable RU Monocegotis, which has a noticeable movement of the apsid line and components with similar brightness values. To questions of the theory of eclipsing variables, intensively developed since the beginning of the thirties at the observatory named after V.P. Engelhardt, Dubyago returned in 1944 - showing that the light curves should not have a kink at the moment of contact of the component disks.

Another joint work with D. Ya. Martynov, L.D. Dubyago, was the processing of visual observations of Mars during the 1926 confrontation. They compiled (according to sketches) a map of part of the surface of Mars , and only those details that were noted by both observers were included in the map. Being an excellent and experienced observer, A.D.Dubyago throughout his life retained a love for observations, and only in recent years the disease deprived him of the physical ability to conduct them. During the years of scientific activity of A.D. Dubyago, the Kazan Observatory, which transmitted a significant part of its instrumentation to the Engelhardt Observatory, could no longer conduct systematic observations on one or another astronomical program. But in all sporadic positional observations at the observatory of the so-called "random phenomena" (comets, minor planets , moon coverings, etc.), A. D. Dubyago was a constant participant.

A. Dubyago showed his talent and skills as an observer in expeditions of the Kazan Observatory, undertaken since 1926 and pursuing cartographic and gravimetric goals. For a decade, A.D. Dubyago was an active participant and often the head of almost all the expeditions of Kazan astronomers to determine astronomical points in the eastern territory of the USSR. He was a consultant on issues related to gravimetric reconnaissance in the Kazan branch of the USSR Academy of Sciences and provided assistance to other institutions on issues of geodesy and cartography .

A. D. Dubyago studied in depth the history of physical and mathematical sciences and for many years taught at the University of Kazan a course in the history of astronomy , captivating the audience with a brilliant presentation. The first scientific work of A.D. Dubyago on the history of astronomy was the article "Comets and their Importance in the General System of Newtonian" Beginnings "". Further work of A.D. Dubyago in this area is characterized by a detailed and accurate analysis of the achievement of science, in close connection with the life and work of scientists. He uncovered the sources and critically examined materials on the astronomical works of N.I. Lobachevsky , but only a part of them was published in articles and comments by A.D. Dubyago in the V volume of the Complete Works of N.I. Lobachevsky. In his translation from French, the "Etudes of Meteors" by F. A. Bredikhin were published in 1954. For this publication, A.D. Dubyago gave scientific comments and an extensive article on the life and works of Bredikhin. An article on Kepler and a number of smaller notes on the history of astronomy were published by A. D. Dubyago in the second edition of the Great Soviet Encyclopedia .

The last years of life

In the 1930s, A.D. Dubyago spent 11 months in prison.

At the University of Kazan, Dubiago conducted a large pedagogical work since 1934 - as an assistant professor , and since 1941 - as a professor; by this time he was awarded the degree of Doctor of Physics and Mathematics .

He taught courses not only at the department of astronomy, but also at the geological and geographical faculties, consisting of the head of the department of geodesy and gravimetry (1941–1946) and the department of theoretical astronomy (1946–1947).

A. D. Dubyago was a permanent member of the commission for comets and meteors of the Astronomical Council of the USSR Academy of Sciences , an active participant and sometimes chairman at the annual plenary meetings of this commission. In the last years of his life, Dubyago was a member of the Astronomical Council.

For the discovery of comets and great observational activity A.D. Dubyago was awarded the gold medal to them. G.A. Tikhova.

The disease did not allow him to fully show his scientific and organizational talent as director (August 1954 - October 1958) of the observatory named after V.P. Engelhardt . Death interrupted the work of A.D. Dubyago on a large scientific commentary for the VI volume of the “Complete Works” by N. I. Lobachevsky. The work on the compilation of the “Theoretical Astronomy” study guide also stopped.

He was buried in the observatory cemetery, not far from the South worlds - the tomb where his father was buried.

Children: daughter - Inga; son is Vladimir.

In 1964, the International Astronomical Union named Alexander Dmitrievich Dubyago a crater on the visible side of the moon .

• Ananyeva L. Ya., Korytnikov S. N. Historical and astronomical research. - Vol. 7. - M .: Fizmatgiz, 1961.
• Dubyago I. A., Nefedyev Yu. A. Alexander Dmitrievich Dubyago (on the 100th anniversary of birth // Earth and the Universe. - 2014. - No. 1. - P. 40-48 . - ISSN 0044-3948 .
• Davydov V.D. Riddles of cometary nuclei. - M .: “Knowledge”, 1988. - S. 25-27.
• Kolchinsky I.G., Korsun A.A., Rodriguez M.G. Astronomers: A Biographical Reference. - 2nd ed., Revised. and additional .. - Kiev: Naukova Dumka, 1986. - 512 p.

• Comet named Dubyago
• Astronomical week from December 17 to December 23, 2012 on the Astronet website