Observatory. Astronomical observatory - what is it? How celestial bodies are studied at the observatory

OBSERVATORY
an institution where scientists observe, study and analyze natural phenomena. The most famous astronomical observatories for the study of stars, galaxies, planets and other celestial objects. There are also meteorological observatories to observe the weather; geophysical observatories for studying atmospheric phenomena, in particular, polar lights; seismic stations for recording vibrations excited in the Earth by earthquakes and volcanoes; observatories for observing cosmic rays and neutrinos. Many observatories are equipped not only with serial instruments for recording natural phenomena, but also with unique instruments that provide the highest possible sensitivity and accuracy under specific observation conditions. In the old days, observatories, as a rule, were built near universities, but then they began to be placed in places with the best conditions for observing the phenomena being studied: seismic observatories - on the slopes of volcanoes, meteorological ones - evenly around the globe, auroral ones (for observing polar lights) - at a distance of about 2000 km from the magnetic pole of the Northern Hemisphere, where a band of intense auroras passes. Astronomical observatories, which use optical telescopes to analyze the light from cosmic sources, require a clean and dry atmosphere free from artificial light, so they tend to be built high in the mountains. Radio observatories are often located in deep valleys, closed on all sides by mountains from artificial radio interference. However, since the observatories employ qualified personnel and regularly visit scientists, whenever possible, they try to locate the observatories not too far from scientific and cultural centers and transport hubs. However, the development of communications makes this problem less and less relevant. This article is about astronomical observatories. In addition, other types of observatories and scientific stations are described in the articles:
EXTRAATMOSPHERIC ASTRONOMY;
VOLCANOES;
GEOLOGY;
EARTHQUAKE;
METEOROLOGY AND CLIMATOLOGY ;
NEUTRINO ASTRONOMY;
RADIOLOCATION ASTRONOMY;
RADIO ASTRONOMY.
HISTORY OF ASTRONOMIC OBSERVATORIES AND TELESCOPES
Ancient world. The oldest facts of astronomical observations that have come down to us are associated with the ancient civilizations of the Middle East. By observing, recording and analyzing the movement of the Sun and Moon across the sky, the priests kept track of time and the calendar, predicted seasons important for agriculture, and also engaged in astrological forecasts. Measuring the movements of heavenly bodies with the help of the simplest instruments, they found that the relative position of the stars in the sky remains unchanged, and the Sun, Moon and planets move relative to the stars and, moreover, very difficult. The priests noted rare celestial phenomena: lunar and solar eclipses, the appearance of comets and new stars. Astronomical observations, bringing practical benefits and helping to shape the worldview, found some support from both religious authorities and civil rulers of different peoples. Many surviving clay tablets from ancient Babylon and Sumer record astronomical observations and calculations. In those days, as now, the observatory served simultaneously as a workshop, instrument storage and data collection center. see also
ASTROLOGY;
SEASONS ;
TIME ;
THE CALENDAR . Little is known about astronomical instruments used before the Ptolemaic era (c. 100 - c. 170 AD). Ptolemy, together with other scientists, collected in the huge library of Alexandria (Egypt) a lot of scattered astronomical records made in various countries over the previous centuries. Using the observations of Hipparchus and his own, Ptolemy compiled a catalog of the positions and brightness of 1022 stars. Following Aristotle, he placed the Earth at the center of the world and believed that all the luminaries revolve around it. Together with colleagues, Ptolemy carried out systematic observations of moving bodies (the Sun, Moon, Mercury, Venus, Mars, Jupiter, Saturn) and developed a detailed mathematical theory to predict their future position in relation to "fixed" stars. With its help, Ptolemy calculated tables of the movement of the stars, which were then used for more than a thousand years.
see also Hipparchus. To measure the slightly changing dimensions of the Sun and Moon, astronomers used a straight bar with a sliding sight in the form of a dark disk or a plate with a round hole. The observer directed the bar at the target and moved the sight along it, achieving an exact match between the hole and the size of the luminary. Ptolemy and his colleagues improved many of the astronomical instruments. Carrying out careful observations with them and using trigonometry converting instrumental readings into position angles, they brought the accuracy of measurements to about 10 ".
(see also PTOLEMY Claudius).
Middle Ages. Due to the political and social upheavals of late antiquity and the early Middle Ages, the development of astronomy in the Mediterranean was suspended. Catalogs and tables of Ptolemy survived, but fewer people knew how to use them, and observations and registration of astronomical events were less and less. However, in the Middle East and Central Asia, astronomy flourished and observatories were built. In the 8th c. Abdullah al-Ma'mun founded a House of Wisdom in Baghdad, similar to the Library of Alexandria, and organized associated observatories in Baghdad and Syria. There, several generations of astronomers studied and developed the work of Ptolemy. Similar institutions flourished in the 10th and 11th centuries. in Cairo. The culmination of that era was a gigantic observatory in Samarkand (now Uzbekistan). There Ulukbek (1394-1449), the grandson of the Asian conqueror Tamerlane (Timur), having built a huge sextant with a radius of 40 m in the form of a south-oriented trench 51 cm wide with marble walls, made observations of the Sun with unprecedented accuracy. Several smaller instruments he used to observe the stars, the moon and the planets.
Renaissance. When in Islamic culture of the 15th century. astronomy flourished, Western Europe rediscovered this great creation of the ancient world.
Copernicus. Nicolaus Copernicus (1473-1543), inspired by the simplicity of the principles of Plato and other Greek philosophers, looked with distrust and anxiety at the geocentric system of Ptolemy, which required cumbersome mathematical calculations to explain the apparent movements of the stars. Copernicus proposed, keeping Ptolemy's approach, to place the Sun in the center of the system, and to consider the Earth as a planet. This greatly simplified the matter, but caused a profound upheaval in people's minds (see also Copernicus Nicholas).
Quiet Brahe. The Danish astronomer T. Brahe (1546-1601) was discouraged by the fact that the Copernican theory more accurately predicted the position of the luminaries than the Ptolemaic theory, but still not quite right. He considered that more accurate observational data would solve the problem, and persuaded King Frederick II to give him Fr. Vienna near Copenhagen. This observatory, named Uraniborg (Castle in the Sky) had many stationary instruments, workshops, a library, a chemical laboratory, bedrooms, a dining room and a kitchen. Tycho even had his own paper mill and printing press. In 1584 he built a new building for observations - Stjerneborg (Star Castle), where he collected the largest and most advanced instruments. True, these were instruments of the same type as in the time of Ptolemy, but Tycho greatly increased their accuracy by replacing wood with metals. He introduced especially precise sights and scales, and came up with mathematical methods for calibrating observations. Tycho and his assistants, observing celestial bodies with the naked eye, achieved with their instruments an accuracy of measurements of 1 ". They systematically measured the positions of the stars and observed the movement of the Sun, Moon and planets, collecting observational data with unprecedented persistence and accuracy.
(see also BRAGE Tycho).

Kepler. Studying Tycho's data, I. Kepler (1571-1630) discovered that the observed revolution of the planets around the Sun cannot be represented as a movement in circles. Kepler had great respect for the results obtained at Uraniborg, and therefore rejected the idea that small discrepancies in the calculated and observed positions of the planets could be caused by errors in Tycho's observations. Continuing the search, Kepler established that the planets move in ellipses, thus laying the foundation for new astronomy and physics.
(see also KEPLER Johann; KEPLER'S LAWS). The work of Tycho and Kepler anticipated many features of modern astronomy, such as the organization of specialized observatories with state support; bringing to perfection instruments, even traditional ones; division of scientists into observers and theorists. New principles of work were approved along with new technology: a telescope came to the aid of the eye in astronomy.
The advent of telescopes. The first refracting telescopes. In 1609 Galileo began using his first homemade telescope. Galileo's observations ushered in an era of visual studies of the heavenly bodies. Telescopes soon spread throughout Europe. Curious people made them themselves or ordered craftsmen and set up small personal observatories, usually in their own homes.
(see also GALILEO Galileo). Galileo's telescope was called a refractor, because the rays of light are refracted in it (Latin refractus - refracted), passing through several glass lenses. In the simplest design, the front lens-objective collects the rays at a focus, creating an image of the object there, and the eyepiece lens located near the eye is used as a magnifying glass to view this image. In Galileo's telescope, a negative lens served as an eyepiece, giving a direct image of rather poor quality with a small field of view. Kepler and Descartes developed the theory of optics, and Kepler proposed a telescope design with an inverted image, but a much larger field of view and magnification than Galileo. This design quickly supplanted the former and became the standard for astronomical telescopes. For example, in 1647, the Polish astronomer Jan Hevelius (1611-1687) used Keplerian telescopes 2.5-3.5 meters long to observe the moon. Initially, he installed them in a small turret on the roof of his house in Gdansk (Poland), and later - on a site with two observation posts, one of which was rotating (see also Hevelius Jan). In Holland, Christian Huygens (1629-1695) and his brother Constantine built very long telescopes with lenses only a few inches in diameter but with enormous focal lengths. This improved the quality of the image, although it made it difficult to work with the tool. In the 1680s, Huygens experimented with 37-meter and 64-meter "aerial telescopes", the lenses of which were placed at the top of the mast and rotated with a long stick or ropes, and the eyepiece was simply held in the hands (see also HUYGENS Christian). Using lenses made by D. Campani, J.D. Cassini (1625-1712) in Bologna and later in Paris carried out observations with aerial telescopes 30 and 41 m long, demonstrating their undoubted advantages, despite the complexity of working with them. Observations were greatly hindered by the vibration of the mast with the lens, the difficulty of aiming it with ropes and cables, as well as the inhomogeneity and turbulence of the air between the lens and the eyepiece, especially strong in the absence of a tube. Newton, the reflecting telescope and the theory of gravitation. In the late 1660s, I. Newton (1643-1727) tried to unravel the nature of light in connection with the problems of refractors. He mistakenly decided that chromatic aberration, i.e. the inability of the lens to collect the rays of all colors into one focus is fundamentally irremovable. Therefore, Newton built the first workable reflecting telescope, in which the role of an objective instead of a lens was played by a concave mirror that collects light at a focus where the image can be viewed through the eyepiece. However, Newton's most important contribution to astronomy was his theoretical work, which showed that the Keplerian laws of planetary motion are a special case of the universal law of gravity. Newton formulated this law and developed mathematical techniques for accurately calculating the motion of the planets. This stimulated the birth of new observatories, where the positions of the Moon, planets and their satellites were measured with the highest accuracy, refining the elements of their orbits using Newton's theory and predicting movement.
see also
HEAVENLY MECHANICS;
GRAVITY ;
NEWTON Isaac.
Watch, micrometer and telescopic sight. No less important than the improvement of the optical part of the telescope was the improvement of its mount and equipment. For astronomical measurements, pendulum clocks have become necessary that can keep pace with local time, which is determined from some observations and used in others.
(see also HOURS). Using a filament micrometer, it was possible to measure very small angles when observing through the eyepiece of a telescope. To increase the accuracy of astrometry, an important role was played by the combination of a telescope with an armillary sphere, a sextant, and other goniometric instruments. As soon as naked eye sights were supplanted by small telescopes, the need arose for much more precise manufacturing and division of angular scales. Largely in connection with the needs of European observatories, the production of small high-precision machine tools has developed.
(see also MEASURING TOOLS).
state observatories. Improvement of astronomical tables. From the second half of the 17th century. for the purposes of navigation and cartography, the governments of various countries began to establish state observatories. At the Royal Academy of Sciences, founded by Louis XIV in Paris in 1666, academicians set about revising astronomical constants and tables from scratch, using Kepler's work as a basis. In 1669, on the initiative of the minister J.-B. Colbert, the Royal Observatory was founded in Paris. It was led by four wonderful generations of Cassini, starting with Jean Dominique. In 1675 the Royal Greenwich Observatory was founded, headed by the first Astronomer Royal D. Flamsteed (1646-1719). Together with the Royal Society, which began its activity in 1647, it became the center of astronomical and geodetic research in England. In the same years, observatories were founded in Copenhagen (Denmark), Lund (Sweden) and Gdansk (Poland) (see also FLEMSTID John). The most important result of the activities of the first observatories was ephemeris - tables of pre-calculated positions of the Sun, Moon and planets, necessary for cartography, navigation and fundamental astronomical research.
Introduction to standard time. State observatories became the keepers of the reference time, which was first distributed using optical signals (flags, signal balloons), and later by telegraph and radio. The current tradition of dropping balloons at midnight on Christmas Eve dates back to the days when signal balloons dropped down a tall mast on the roof of the observatory at precisely the right time, allowing the captains of ships in the harbor to check their chronometers before sailing.
Definition of longitudes. An extremely important task of the state observatories of that era was to determine the coordinates sea ​​vessels. Geographic latitude is easy to find by the angle of the North Star above the horizon. But longitude is much more difficult to determine. Some methods were based on the moments of eclipses of the moons of Jupiter; others - on the position of the moon relative to the stars. But the most reliable methods required high-precision chronometers capable of keeping the time of the observatory near the port of departure during the voyage.
Development of the Greenwich and Paris observatories. In the 19th century the most important astronomical centers remained public and some private observatories in Europe. In the 1886 list of observatories we find 150 in Europe, 42 in North America and 29 elsewhere. The Greenwich Observatory by the end of the century had a 76-cm ​​reflector, 71-, 66- and 33-cm refractors and many auxiliary instruments. She was actively involved in astrometry, timekeeping, solar physics and astrophysics, as well as geodesy, meteorology, magnetic and other observations. The Paris Observatory also had accurate modern instruments and conducted programs similar to Greenwich.
new observatories. The Pulkovo Astronomical Observatory of the Imperial Academy of Sciences in St. Petersburg, built in 1839, quickly gained respect and honor. Its growing team was involved in astrometry, determination of fundamental constants, spectroscopy, timekeeping, and a variety of geophysical programs. The Potsdam Observatory in Germany, opened in 1874, soon became an authoritative organization known for its work on solar physics, astrophysics, and photographic surveys of the sky.
Building large telescopes. Reflector or refractor? Although Newton's reflecting telescope was an important invention, for several decades it was regarded by astronomers only as a tool to complement refractors. At first, reflectors were made by the observers themselves for their own small observatories. But by the end of the 18th century. this was taken up by the fledgling optical industry, sensing the need of a growing number of astronomers and surveyors. Observers were able to choose from many types of reflectors and refractors, each with advantages and disadvantages. Refracting telescopes with high-quality glass lenses gave a better image than reflectors, and their tube was more compact and stiffer. But reflectors could be made of a much larger diameter, and the images in them were not distorted by colored borders, as with refractors. In the reflector, weak objects are better seen, since there are no light losses in the glasses. However, the speculum alloy, from which the mirrors were made, quickly faded and required frequent repolishing (they still did not know how to cover the surface with a thin mirror layer).
Herschel. In the 1770s, the meticulous and stubborn self-taught astronomer W. Herschel built several Newtonian telescopes, bringing the diameter to 46 cm and the focal length to 6 m. The high quality of his mirrors made it possible to use very strong magnification. Using one of his telescopes, Herschel discovered the planet Uranus, as well as thousands of double stars and nebulae. Many telescopes were built in those years, but usually they were built and used by lone enthusiasts, without organizing an observatory in the modern sense.
(see also HERSHEL, WILLIAM). Herschel and other astronomers tried to build larger reflectors. But the massive mirrors buckled and lost their shape as the telescope changed position. The limit for metal mirrors was reached in Ireland by W. Parsons (Lord Ross), who created a reflector with a diameter of 1.8 m for his home observatory.
Construction of large telescopes. Industrial magnates and nouveaux riches in the United States accumulated at the end of the 19th century. gigantic wealth, and some of them turned to philanthropy. Thus, J. Leek (1796-1876), who made his fortune on the gold rush, bequeathed to establish an observatory on Mount Hamilton, 65 km from Santa Cruz (California). Its main instrument was a 91-cm refractor, then the largest in the world, manufactured by the well-known company Alvan Clark and Sons and installed in 1888. And in 1896, at the Lick Observatory, a 36-inch Crossley reflector, then the largest in the USA, began to operate. . Astronomer J. Hale (1868-1938) convinced the Chicago tram magnate C. Yerkes to finance the construction of an even larger observatory for the University of Chicago. It was founded in 1895 in Williams Bay, Wisconsin, with a 40-inch refractor, still and probably forever the largest in the world (see also George Ellery HALE). Having organized the Yerkes Observatory, Hale developed a stormy activity to attract funds from various sources, including the steel magnate A. Carnegie, to build an observatory in the best place for observations in California. Equipped with several Hale-design solar telescopes and a 152 cm reflector, the Mount Wilson Observatory in the San Gabriel Mountains north of Pasadena, California, soon became an astronomical mecca. Having gained the necessary experience, Hale organized the creation of a reflector of unprecedented size. Named after the main sponsor, the 100-inch telescope. Hooker entered service in 1917; but before that, many engineering problems had to be overcome, which at first seemed insoluble. The first was to cast a glass disc of the right size and cool it slowly to produce high quality glass. Grinding and polishing the mirror to give it the required shape took more than six years and required the creation of unique machines. The final stage of polishing and checking the mirror was carried out in a special room with perfect cleanliness and temperature control. The mechanisms of the telescope, the building and the dome of its tower, built on the top of Mount Wilson (Mount Wilson) with a height of 1700 m, were considered an engineering miracle of that time. Inspired by the fine workmanship of the 100-inch instrument, Hale devoted the rest of his life to building the gigantic 200-inch telescope. 10 years after his death and due to a delay caused by the Second World War, the telescope. Hale entered service in 1948 on top of the 1700-meter Mount Palomar (Mount Palomar), 64 km northeast of San Diego (pc. California). It was a scientific and technical miracle of those days. For almost 30 years, this telescope remained the largest in the world, and many astronomers and engineers believed that it would never be surpassed.

But the advent of computers contributed to the further expansion of the construction of telescopes. In 1976, on the 2100-meter Mount Semirodniki near the village of Zelenchukskaya (Northern Caucasus, Russia), a 6-meter BTA telescope (Large Azimuthal Telescope) began to operate, demonstrating the practical limit of the technology of a "thick and strong" mirror.

The way to build large mirrors that can collect more light, and therefore see farther and better, lies through new technologies: in recent years, methods for manufacturing thin and prefabricated mirrors have been developed. Thin mirrors with a diameter of 8.2 m (with a thickness of about 20 cm) are already in operation on the telescopes of the Southern Observatory in Chile. Their shape is controlled by a complex system of mechanical "fingers" controlled by a computer. The success of this technology has led to the development of several similar projects in different countries. To test the idea of ​​a compound mirror, the Smithsonian Astrophysical Observatory built a telescope in 1979 with a lens of six 183-cm mirrors, equivalent in area to one 4.5-meter mirror. This multimirror telescope, located on Mount Hopkins 50 km south of Tucson, Arizona, proved to be very effective, and this approach was used in the construction of two 10-meter telescopes to them. W. Keka at the Mauna Kea Observatory (Hawaii). Each giant mirror is composed of 36 hexagonal segments 183 cm across, computer-controlled to produce a single image. Although the image quality is not yet high, it is possible to obtain spectra of very distant and faint objects that are inaccessible to other telescopes. Therefore, in the early 2000s, it is planned to put into operation several more multimirror telescopes with effective apertures of 9–25 m.

AT THE TOP OF MAUNA KEA, an ancient volcano in Hawaii, there are dozens of telescopes. Astronomers are attracted here by the high altitude and very dry, clean air. At the bottom right, through the open slit of the tower, the mirror of the Kek I telescope is clearly visible, and at the bottom left - the tower of the Kek II telescope under construction.

HARDWARE DEVELOPMENT
The photo. In the middle of the 19th century a few enthusiasts have started using photography to record images seen through a telescope. With the increase in the sensitivity of emulsions, glass photographic plates became the main means of recording astrophysical data. In addition to traditional handwritten observation logs, precious "glass libraries" appeared in observatories. A photographic plate is capable of accumulating the faint light of distant objects and capturing details inaccessible to the eye. With the use of photography in astronomy, new types of telescopes were required, such as wide-view cameras capable of recording large areas of the sky at once in order to create photo atlases instead of drawn maps. In combination with large-diameter reflectors, photography and a spectrograph made it possible to study faint objects. In the 1920s, using the 100-inch Mount Wilson Observatory telescope, E. Hubble (1889-1953) classified faint nebulae and proved that many of them are giant galaxies like the Milky Way. In addition, Hubble discovered that galaxies are rapidly flying apart from each other. This completely changed the ideas of astronomers about the structure and evolution of the Universe, but only a few observatories that had powerful telescopes for observing faint distant galaxies were able to do such research.
see also
COSMOLOGY;
GALAXIES;
Hubble Edwin Powell;
NEBLES.
Spectroscopy. Appeared almost simultaneously with photography, spectroscopy allowed astronomers to determine their chemical composition from the analysis of the light of stars, and to study the motion of stars and galaxies by the Doppler shift of lines in the spectra. The development of physics at the beginning of the 20th century. helped to decipher the spectrograms. For the first time, it became possible to study the composition of inaccessible celestial bodies. This task proved to be within the power of modest university observatories, since a large telescope is not needed to obtain the spectra of bright objects. Thus, the Harvard College Observatory was one of the first to engage in spectroscopy and collected a huge collection of stellar spectra. Its employees have classified thousands of stellar spectra and created the basis for studying stellar evolution. Combining this data with quantum physics, theorists understood the nature of the source of stellar energy. In the 20th century detectors of infrared radiation coming from cold stars, from the atmospheres and from the surface of planets were created. Visual observations, as an insufficiently sensitive and objective measure of the brightness of stars, were supplanted first by photographic plates and then by electronic instruments (see also SPECTROSCOPY).
ASTRONOMY AFTER WORLD WAR II
Strengthening state support. After the war, new technologies that were born in army laboratories became available to scientists: radio and radar equipment, sensitive electronic light receivers, and computers. The governments of industrialized countries realized the importance of scientific research for national security and began to allocate considerable funds for scientific work and education.
US National Observatories. In the early 1950s, the US National Science Foundation approached astronomers to come up with proposals for a nationwide observatory that would be in the best possible location and accessible to all qualified scientists. By the 1960s, two groups of organizations had emerged: the Association of Universities for Research in Astronomy (AURA), which created the concept of the National Optical Astronomy Observatories (NOAO) at the 2100-meter summit of Kitt Peak near Tucson, Arizona, and the Amalgamated Universities, which developed the project National Radio Astronomy Observatory (NRAO) in Deer Creek Valley near Green Bank, WV.

US NATIONAL OBSERVATORY KITT-PEAK near Tucson, Arizona. Among its largest instruments are the McMas Solar Telescope (bottom), the 4-m Mayall Telescope (top right), and the 3.5-m WIYN Telescope of the Wisconsin, Indiana, Yale and NOAO Joint Observatory (far left).

By 1990, NOAO had 15 telescopes up to 4 m in diameter on Kitt Peak. AURA also established the Inter-American Observatory in Sierra Tololo (Chilean Andes) at an altitude of 2200 m, where the southern sky has been studied since 1967. In addition to Green Bank, where the largest radio telescope (43 m in diameter) is installed on an equatorial mount, NRAO also has a 12-meter millimeter-wave telescope on Kitt Peak and a VLA (Very Large Array) system of 27 radio telescopes with diameters of 25 m on the San desert plain. -Augustine near Socorro (pc. New Mexico). The National Radio and Ionospheric Center on the island of Puerto Rico became a major American observatory. His radio telescope with the world's largest spherical mirror with a diameter of 305 m lies motionless in a natural recess among the mountains and is used for radio and radar astronomy.

The permanent employees of the national observatories monitor the serviceability of the equipment, develop new instruments and conduct their own research programs. However, any scientist can apply to observe and, if approved by the Scientific Research Coordination Committee, receive time to work on the telescope. This allows scientists from poor institutions to use the most advanced equipment.
Southern sky observations. Much of the southern sky is not visible from most observatories in Europe and the United States, although it is the southern sky that is considered especially valuable for astronomy, since it contains the center of the Milky Way and many important galaxies, including the Magellanic Clouds - two small galaxies neighboring us. The first maps of the southern sky were made by the English astronomer E. Halley, who worked from 1676 to 1678 on the island of St. Helena, and the French astronomer N. Lacaille, who worked from 1751 to 1753 in southern Africa. In 1820, the British Bureau of Longitudes founded the Royal Observatory at the Cape of Good Hope, first equipping it with only a telescope for astrometric measurements, and then with a complete set of instruments for various programs. In 1869 a 122-cm reflector was installed in Melbourne (Australia); later he was transferred to Mount Stromlo, where, after 1905, an astrophysical observatory began to grow. At the end of the 20th century, when the conditions for observations at the old observatories of the Northern Hemisphere began to deteriorate due to strong urbanization, European countries began to actively build observatories with large telescopes in Chile, Australia, Central Asia, the Canary and Hawaiian Islands.
observatories above the earth. Astronomers began using high-altitude balloons as observation platforms as early as the 1930s and continue such research to this day. In the 1950s, instruments were installed on high-altitude aircraft that became flying observatories. Extra-atmospheric observations began in 1946, when US scientists on captured German V-2 rockets raised detectors into the stratosphere to observe the ultraviolet radiation of the Sun. The first artificial satellite was launched in the USSR on October 4, 1957, and already in 1958 the Soviet Luna-3 station photographed the far side of the Moon. Then flights to the planets began to be carried out and specialized astronomical satellites appeared for observing the Sun and stars. In recent years, several astronomical satellites have been constantly operating in near-Earth and other orbits, studying the sky in all ranges of the spectrum.
work at the observatory. In former times, the life and work of an astronomer depended entirely on the capabilities of his observatory, since communication and travel were slow and difficult. At the beginning of the 20th century Hale created the Mount Wilson Observatory as a center for solar and stellar astrophysics, capable of conducting not only telescopic and spectral observations, but also the necessary laboratory research. He sought to ensure that Mount Wilson had everything that was necessary for life and work, just as Tycho did on the island of Ven. Until now, some large observatories on mountain peaks are closed communities of scientists and engineers living in a hostel and working at night according to their programs. But gradually this style is changing. In search of the most favorable places for observation, observatories are located in remote areas where it is difficult to live permanently. Visiting scientists stay at the observatory from a few days to several months to make specific observations. The capabilities of modern electronics make it possible to conduct remote observations without visiting the observatory at all, or to build fully automatic telescopes in hard-to-reach places that independently work according to the intended program. Observations with the help of space telescopes have a certain specificity. At first, many astronomers accustomed to working independently with the instrument felt uncomfortable within the framework of space astronomy, separated from the telescope not only by space, but also by many engineers and complex instructions. However, in the 1980s, at many ground-based observatories, the control of the telescope was transferred from simple consoles located directly at the telescope to a special room stuffed with computers and sometimes located in a separate building. Instead of aiming the main telescope at an object by looking into a small search telescope mounted on it and pressing buttons on a small hand-held remote control, the astronomer now sits in front of the TV guide screen and manipulates the joystick. Often an astronomer simply sends over the Internet to an observatory detailed program observations and, when they are carried out, receives the results directly into your computer. Therefore, the style of working with ground-based and space telescopes is becoming more and more similar.
MODERN GROUND OBSERVATORIES
optical observatories. The site for the construction of an optical observatory is usually chosen away from cities with their bright night illumination and smog. Usually this is the top of the mountain, where the layer of the atmosphere is thinner, through which you have to make observations. It is desirable that the air is dry and clean, and the wind is not particularly strong. Ideally, observatories should be evenly distributed over the surface of the Earth so that objects in the northern and southern sky can be observed at any time. However, historically, most of the observatories are located in Europe and North America, so the sky of the Northern Hemisphere is better studied. In recent decades, large observatories have begun to be built in the southern hemisphere and near the equator, from where both the northern and southern skies can be observed. The ancient volcano Mauna Kea on about. Hawaii with a height of more than 4 km is considered the best place in the world for astronomical observations. In the 1990s, dozens of telescopes from different countries settled there.
Tower. Telescopes are very sensitive instruments. To protect them from bad weather and temperature changes, they are placed in special buildings - astronomical towers. Small towers are rectangular in shape with a flat retractable roof. Towers of large telescopes are usually made round with a hemispherical rotating dome, in which a narrow slit is opened for observations. Such a dome well protects the telescope from the wind during operation. This is important because the wind sways the telescope and causes the image to shake. The vibration of the ground and the building of the tower also negatively affects the quality of the images. Therefore, the telescope is mounted on a separate foundation, not connected with the foundation of the tower. Inside the tower or near it, a ventilation system for the dome space and an installation for vacuum deposition on the telescope mirror of a reflective aluminum layer, which tarnishes with time, are mounted.
Mount. To aim at the luminary, the telescope must rotate around one or two axes. The first type includes the meridian circle and the transit instrument - small telescopes that rotate around a horizontal axis in the plane of the celestial meridian. Moving from east to west, each luminary crosses this plane twice a day. With the help of a transit instrument, the moments of the passage of stars through the meridian are determined and thus the speed of the Earth's rotation is specified; this is necessary for the accurate time service. The meridian circle allows you to measure not only the moments, but also the place where the star crosses the meridian; this is necessary to create accurate maps of the starry sky. In modern telescopes, direct visual observation is practically not used. They are mainly used to photograph celestial objects or to register their light with electronic detectors; the exposure sometimes reaches several hours. During this time, the telescope must be accurately aimed at the object. Therefore, with the help of a clock mechanism, it rotates at a constant speed around the clock axis (parallel to the axis of rotation of the Earth) from east to west following the star, thereby compensating for the rotation of the Earth from west to east. The second axis, perpendicular to the clock, is called the declination axis; it serves to point the telescope in the north-south direction. This design is called an equatorial mount and is used for almost all telescopes, with the exception of the largest, for which the alt-azimuth mount turned out to be more compact and cheaper. On it, the telescope follows the luminary, turning simultaneously with variable speed around two axes - vertical and horizontal. This greatly complicates the work of the watch mechanism, requiring computer control.

Telescope refractor has a lens. Since rays of different colors are refracted differently in glass, a lens objective is calculated so that it gives a sharp image in focus in the rays of a single color. Old refractors were designed for visual observation and therefore gave a clear image in the yellow beams. With the advent of photography, photographic telescopes began to be built - astrographs, which give a clear image in blue rays, to which photographic emulsion is sensitive. Later, emulsions appeared that were sensitive to yellow, red, and even infrared light. They can be used for photography with visual refractors. The image size depends on the focal length of the lens. The 102-cm Yerkes refractor has a focal length of 19 m, so the diameter of the lunar disk at its focus is about 17 cm. The size of the photographic plates of this telescope is 20x25 cm; the full moon fits easily on them. Astronomers use glass photographic plates because of their high rigidity: even after 100 years of storage, they do not deform and make it possible to measure the relative position of stellar images with an accuracy of 3 microns, which for large refractors like the Yerk's corresponds to an arc of 0.03 "in the sky.
reflecting telescope as a lens has a concave mirror. Its advantage over a refractor is that rays of any color are reflected from the mirror in the same way, providing a clear image. In addition, a mirror lens can be made much larger than a lens lens, since the glass blank for the mirror may not be transparent inside; it can be saved from deformation under its own weight by placing it in a special frame that supports the mirror from below. The larger the diameter of the lens, the more light the telescope collects and the weaker and more distant objects are able to "see". For many years, the 6th reflector of the BTA (Russia) and the 5th reflector of the Palomar Observatory (USA) were the largest in the world. But now, two telescopes with 10-meter compound mirrors are operating at the Mauna Kea Observatory on Hawaii, and several telescopes with monolithic mirrors with a diameter of 8-9 meters are being built. Table 1.
THE LARGEST TELESCOPES IN THE WORLD
___
__Diameter ______Observatory ______Location and year of objective (m) ________________construction/dismantling

REFLECTORS

10.0 Mauna Kea Hawaii (USA) 1996 10.0 Mauna Kea Hawaii (USA) 1993 9.2 McDonald Texas (USA) 1997 8.3 National Japan Hawaii (USA) 1999 8.2 Sierra Paranal European South Mountain (Chile) 1998 8.2 Sierra Paranal European South Mountain (Chile) 1999 8.2 Sierra Paranal European South Mountain (Chile) 2000 8.1 Gemini North Hawaii (USA) 1999 6.5 University of Arizona Mount Hopkins (Arizona) 1999 6.0 Special Astrophysical Academy of Sciences of Russia stan. Zelenchukskaya (Russia) 1976 5.0 Palomar Mountain Palomar (California) 1949 1.8*6=4.5 University of Arizona Hopkins Mountain (Arizona) 1979/1998 4.2 Roca de los Muchachos Canary Islands (Spain) 1986 4.0 Inter-American Sierra Tololo (Chile) 1975 3.9 Anglo-Australian Siding Spring (Australia) 1975 3.8 Kitt Peak National Tucson (Arizona) 1974 3.8 Mauna Kea (IR) Hawaii ( USA) 1979 3.6 European South La Silla (Chile) 1976 3.6 Mauna Kea Hawaii (USA) 1979 3.5 Roca de los Muchachos Canary Islands (Spain) 1989 3.5 Intercollegiate Sacramento Peak (unit) . New Mexico) 1991 3.5 German-Spanish Calar Alto (Spain) 1983

REFRACTORS

1.02 Yerke Williams Bay (Wisconsin) 1897 0.91 Lick Hill Hamilton (CA) 1888 0.83 Parisian Meudon (France) 1893 0.81 Potsdam Potsdam (Germany) 1899 0.76 French Southern Nice ( France) 1880 0.76 Allegheny Pittsburgh (Pennsylvania) 1917 0.76 Pulkovo St. Petersburg 1885/1941

SCHMIDT CAMERAS*

1.3-2.0 K. Schwarzschild Tautenburg (Germany) 1960 1.2-1.8 Palomar Mountain Palomar (California) 1948 1.2-1.8 Anglo-Australian Siding Spring (Australia) 1973 1, 1-1.5 Astronomical Tokyo (Japan) 1975 1.0-1.6 European Southern Chile 1972

SOLAR

1.60 Kitt Peak National Tucson (Arizona) 1962 1.50 Sacramento Peak (B)* Sunspot (New Mexico) 1969 1.00 Astrophysical Crimea (Ukraine) 1975 0.90 Kitt Peak (2 add.)* Tucson (Arizona) 1962 0.70 Kitt Peak (B)* Tucson (Arizona) 1975 0.70 Tenerife (Spain) 1988 0.66 Mitaka Tokyo (Japan) 1920 0.64 Cambridge Cambridge (England) 1820

Note: For Schmidt cameras, the diameter of the correction plate and mirror are indicated; for solar telescopes: (B) - vacuum; 2 additional - two additional telescopes in a common housing with a 1.6-m telescope.
SLR cameras. The disadvantage of reflectors is that they give a clear image only near the center of the field of view. This does not interfere if they study one object. But patrol work, for example, the search for new asteroids or comets, requires photographing large areas of the sky at once. An ordinary reflector is not suitable for this. The German optician B. Schmidt in 1932 created a combined telescope, in which the shortcomings of the main mirror are corrected with the help of a thin lens of complex shape located in front of it - a correction plate. The Schmidt camera of the Palomar Observatory acquires an image of a 6°6° sky region on a photographic plate 35x35 cm. Another design of a wide-angle camera was created by D.D. Maksutov in 1941 in Russia. It is simpler than the Schmidt camera, since the role of the correction plate in it is played by a simple thick lens - the meniscus.
The work of optical observatories. Now more than 100 large observatories operate in more than 30 countries of the world. Usually, each of them independently or in cooperation with others conducts several long-term observation programs. Astrometric measurements. Large national observatories - the US Naval Observatory, the Royal Greenwich Observatory in the UK (closed in 1998), Pulkovo in Russia, etc. - regularly measure the positions of stars and planets in the sky. This is very delicate work; it is in it that the highest "astronomical" accuracy of measurements is achieved, on the basis of which catalogs of the position and movement of the stars are created, which are necessary for terrestrial and space navigation, to determine the spatial position of stars, to clarify the laws of planetary motion. For example, by measuring the coordinates of stars at intervals of half a year, you can see that some of them experience fluctuations associated with the movement of the Earth in its orbit (the parallax effect). The distance to the stars is determined by the magnitude of this shift: the smaller the shift, the greater the distance. From Earth, astronomers can measure a displacement of 0.01" (the thickness of a match 40 km away!), which corresponds to a distance of 100 parsecs.
Meteor Patrol. Multiple wide-angle cameras spaced a long way apart continuously photograph the night sky to determine meteor trajectories and possible impact sites. For the first time, these observations from two stations began at the Harvard Observatory (USA) in 1936 and were regularly carried out under the guidance of F. Whipple until 1951. In 1951-1977, the same work was carried out at the Ondrejovskaya Observatory (Czech Republic). Since 1938 in the USSR, photographic observations of meteors have been carried out in Dushanbe and Odessa. Observations of meteors make it possible to study not only the composition of cosmic dust particles, but also the structure of the earth's atmosphere at altitudes of 50–100 km, which are difficult to access for direct sounding. The meteor patrol received the greatest development in the form of three "ballistic networks" - in the USA, Canada and Europe. For example, the Prairie Network of the Smithsonian Observatory (USA) used 2.5-cm automatic cameras at 16 stations located at a distance of 260 km around Lincoln (Nebraska) to photograph bright meteors - fireballs. Since 1963, the Czech fireball network has developed, which later turned into a European network of 43 stations in the Czech Republic, Slovakia, Germany, Belgium, the Netherlands, Austria and Switzerland. Now it is the only operating fireball network. Its stations are equipped with fish-eye cameras that allow photographing the entire hemisphere of the sky at once. With the help of fireball networks, several times it was possible to find meteorites that fell to the ground and restore their orbit before a collision with the Earth.
Sun observations. Many observatories regularly photograph the Sun. The number of dark spots on its surface serves as an indicator of activity, which periodically increases on average every 11 years, leading to disruption of radio communications, increased auroras and other changes in the Earth's atmosphere. The most important instrument for studying the Sun is the spectrograph. By passing sunlight through a narrow slit at the focus of a telescope and then decomposing it into a spectrum using a prism or diffraction grating, one can find out the chemical composition of the solar atmosphere, the speed of gas movement in it, its temperature and magnetic field. Using a spectroheliograph, you can take photographs of the Sun in the emission line of a single element, such as hydrogen or calcium. Prominences are clearly visible on them - huge clouds of gas flying up above the surface of the Sun. Of great interest is the hot rarefied region of the solar atmosphere - the corona, which is usually visible only during total solar eclipses. However, some high-mountain observatories have created special telescopes - non-eclipsing coronographs, in which a small shutter ("artificial moon") closes the bright disk of the Sun, making it possible to observe its corona at any time. Such observations are carried out on Capri Island (Italy), at the Sacramento Peak Observatory (New Mexico, USA), Pic du Midi (French Pyrenees) and others.

Observations of the Moon and planets. The surface of planets, satellites, asteroids and comets is studied using spectrographs and polarimeters, determining the chemical composition of the atmosphere and the features of the solid surface. Very active in these observations are the Lovell Observatory (Arizona), Meudon and Pic-du-Midi (France), and Krymskaya (Ukraine). Although in recent years many remarkable results have been obtained with the help of spacecraft, ground-based observations have not lost their relevance and annually bring new discoveries.
Star observations. By measuring the intensity of the lines in the spectrum of a star, astronomers determine the abundance of chemical elements and the temperature of the gas in its atmosphere. The position of the lines on the basis of the Doppler effect determines the speed of the star as a whole, and the shape of the line profile determines the speed of gas flows in the atmosphere of the star and the speed of its rotation around the axis. Often in the spectra of stars, lines of rarefied interstellar matter are visible, located between the star and the earthly observer. By systematically observing the spectrum of one star, one can study the oscillations of its surface, establish the presence of satellites and streams of matter, sometimes flowing from one star to another. Using a spectrograph placed at the focus of the telescope, it is possible to obtain a detailed spectrum of only one star in tens of minutes of exposure. For a mass study of the spectra of stars, a large prism is placed in front of the lens of a wide-angle (Schmidt or Maksutov) camera. In this case, a section of the sky is obtained on a photographic plate, where each image of a star is represented by its spectrum, the quality of which is not high, but sufficient for mass study of stars. Such observations have been carried out for many years at the Observatory of the University of Michigan (USA) and at the Abastumani Observatory (Georgia). Recently, fiber-optic spectrographs have been created: light guides are placed at the focus of the telescope; each of them is installed with one end on the image of a star, and with the other - on the slit of the spectrograph. So for one exposure, you can get detailed spectra of hundreds of stars. By passing the light of a star through various filters and measuring its brightness, one can determine the color of a star, which indicates the temperature of its surface (the bluer, the hotter) and the amount of interstellar dust lying between the star and the observer (the more dust, the redder the star). Many stars periodically or randomly change their brightness - they are called variables. Changes in brightness associated with fluctuations in the surface of a star or with mutual eclipses of the components of binary systems tell a lot about the internal structure of stars. When investigating variable stars, it is important to have long and dense series of observations. Therefore, astronomers often involve amateurs in this work: even eye estimates of the brightness of stars through binoculars or a small telescope are of scientific value. Astronomy enthusiasts often join clubs for joint observations. In addition to studying variable stars, they often discover comets and outbursts of new stars, which also make a significant contribution to astronomy. Faint stars are studied only with the help of large telescopes with photometers. For example, a telescope with a diameter of 1 m collects 25,000 times more light than the pupil of the human eye. The use of a photographic plate during long exposure increases the sensitivity of the system by another thousand times. Modern photometers with electronic light receivers, such as a photomultiplier tube, an electron-optical converter, or a semiconductor CCD matrix, are ten times more sensitive than photographic plates and make it possible to directly record measurement results in computer memory.
Observations of faint objects. Observations of distant stars and galaxies are carried out using the largest telescopes with a diameter of 4 to 10 m. The leading role in this belongs to the observatories Mauna Kea (Hawaii), Palomarskaya (California), La Silla and Sierra Tololo (Chile), Special Astrophysical Observatory (Russia ). For the mass study of faint objects, large Schmidt cameras are used at the Tonantzintla (Mexico), Mount Stromlo (Australia), Bloemfontein (South Africa), and Byurakan (Armenia) observatories. These observations make it possible to penetrate most deeply into the Universe and study its structure and origin.
Programs of joint observations. Many observing programs are carried out jointly by several observatories, the interaction of which is supported by the International Astronomical Union (IAU). It unites about 8,000 astronomers from all over the world, has 50 commissions in various areas of science, gathers large Assemblies once every three years, and annually organizes several large symposiums and colloquia. Each commission of the IAU coordinates observations of objects of a certain class: planets, comets, variable stars, etc. The IAU coordinates the work of many observatories in compiling star charts, atlases and catalogs. The Smithsonian Astrophysical Observatory (USA) operates the Central Bureau of Astronomical Telegrams, which quickly notifies all astronomers about unexpected events - outbursts of new and supernova stars, the discovery of new comets, etc.
RADIO OBSERVATORIES
The development of radio communication technology in the 1930s-1940s made it possible to begin radio observations of space bodies. This new "window" to the Universe has brought many amazing discoveries. Of the entire spectrum of electromagnetic radiation, only optical and radio waves pass through the atmosphere to the surface of the Earth. In this case, the "radio window" is much wider than the optical one: it extends from millimeter wavelengths to tens of meters. In addition to objects known in optical astronomy - the Sun, planets and hot nebulae - previously unknown objects turned out to be sources of radio waves: cold clouds of interstellar gas, galactic nuclei and exploding stars.
Types of radio telescopes. The radio emission of space objects is very weak. To notice it against the background of natural and artificial interference, highly directional antennas are needed that receive a signal from only one point in the sky. These antennas are of two types. For short-wavelength radiation, they are made of metal in the form of a concave parabolic mirror (like an optical telescope), which concentrates the radiation incident on it at the focus. Such reflectors with a diameter of up to 100 m - full-turn - are able to look at any part of the sky (like an optical telescope). Larger antennas are made in the form of a parabolic cylinder that can rotate only in the meridian plane (like an optical meridian circle). Rotation around the second axis ensures the rotation of the Earth. The largest paraboloids are made immobile using natural hollows in the ground. They can only observe a limited area of ​​the sky. Table 2.
LARGEST RADIO TELESCOPES
________________________________________________
Largest __ Observatory _____ Location and year _ size ____________________ of structure/dismantling
antenna (m)
________________________________________________
1000 1 Lebedev Physical Institute, RAS Serpukhov (Russia) 1963 600 1 Special Astrophysical Academy of Sciences of Russia Sev.Kavkaz (Russia) 1975 305 2 Ionospheric Arecibo Arecibo (Puerto Rico) 1963 305 1 Meudon Meudon (France) 1964 183 University of Illinois Danville (Illinois) 1962 122 University of California Hat Creek (California) 1960 110 1 Ohio University Delaware (Ohio) 1962 107 Stanford Radio Laboratory Stanford (California) 1959 100 Institute. Max Planck Bonn (Germany) 1971 76 Jodrell Bank Macclesfield (England) 1957 ________________________________________________
Notes:
1 an antenna with an unfilled aperture;
2 fixed antenna. ________________________________________________
Antennas for long-wave radiation are mounted from a large number of simple metal dipoles placed over an area of ​​​​several square kilometers and interconnected so that the signals received by them amplify each other only if they come from a certain direction. The larger the antenna, the narrower the area in the sky it examines, while giving a clearer picture of the object. An example of such an instrument is the UTR-2 (Ukrainian T-shaped radio telescope) of the Kharkov Institute of Radiophysics and Electronics of the Academy of Sciences of Ukraine. The length of its two arms is 1860 and 900 m; it is the most advanced instrument in the world for studying decameter radiation in the range of 12-30 m. The principle of combining several antennas into a system is also used for parabolic radio telescopes: by combining signals received from one object by several giant antenna. This significantly improves the quality of the received radio images. Such systems are called radio interferometers, since the signals from different antennas, when added, interfere with each other. Images from radio interferometers are no worse than optical ones in quality: the smallest details are about 1 ", and if you combine signals from antennas located on different continents, then the size of the smallest details on the object image can be reduced by another thousand times. The signal collected by the antenna is detected and amplified a special receiver - a radiometer, which is usually tuned to one fixed frequency or changes tuning in a narrow frequency band. To reduce their own noise, radiometers are often cooled to a very low temperature. The amplified signal is recorded on a tape recorder or computer. The power of the received signal is usually expressed in terms of "antenna temperature", as if there were an absolutely black body of a given temperature in place of the antenna, emitting the same power. By measuring the signal power at different frequencies, a radio spectrum is built, the shape of which allows one to judge the mechanism of radiation and the physical nature of the object. Radio astronomy observations can be carried out but whose and during the day, if interference from industrial facilities does not interfere: sparking electric motors, broadcast radio stations, radars. For this reason, radio observatories are usually set up far from cities. Radio astronomers do not have special requirements for the quality of the atmosphere, but when observing at waves shorter than 3 cm, the atmosphere becomes a hindrance, so short-wave antennas are preferred to be placed high in the mountains. Some radio telescopes are used as radars, sending out a powerful signal and receiving a pulse reflected from the object. This allows you to accurately determine the distance to planets and asteroids, measure their speed, and even build a surface map. This is how maps of the surface of Venus were obtained, which is not visible in optics through its dense atmosphere.
see also
RADIO ASTRONOMY;
RADAR ASTRONOMY.
radio astronomical observations. Depending on the parameters of the antenna and the available equipment, each radio observatory specializes in a certain class of observation objects. The sun, due to its proximity to the earth, is a powerful source of radio waves. The radio emission coming from its atmosphere is constantly recorded - this makes it possible to predict solar activity. Active processes take place in the magnetosphere of Jupiter and Saturn, radio pulses from which are regularly observed at the observatories of Florida, Santiago and Yale University. The largest antennas in England, the USA and Russia are used for planetary radar. A remarkable discovery was the radiation of interstellar hydrogen at a wavelength of 21 cm discovered at the Leiden Observatory (Netherlands). Then, dozens of other atoms and complex molecules, including organic ones, were found in the interstellar medium using radio lines. Molecules radiate especially intensely at millimeter waves, for the reception of which special parabolic antennas with a high-precision surface are created. First, at the Cambridge Radio Observatory (England), and then in others, since the beginning of the 1950s, systematic surveys of the entire sky have been carried out to identify radio sources. Some of them coincide with known optical objects, but many have no analogues in other radiation ranges and, apparently, are very distant objects. In the early 1960s, after discovering faint starlike objects coinciding with radio sources, astronomers discovered quasars, very distant galaxies with incredibly active nuclei. From time to time, some radio telescopes attempt to search for signals from extraterrestrial civilizations. The first project of this kind was the US National Radio Astronomy Observatory project in 1960 to search for signals from the planets of nearby stars. Like all subsequent searches, it brought a negative result.
EXTRAATMOSPHERIC ASTRONOMY
Since the Earth's atmosphere does not pass X-ray, infrared, ultraviolet and some types of radio emission to the surface of the planet, instruments for their study are installed on artificial Earth satellites, space stations or interplanetary vehicles. These devices require low weight and high reliability. Usually, specialized astronomical satellites are launched to observe in a certain range of the spectrum. Even optical observations are preferably carried out outside the atmosphere, which significantly distorts the images of objects. Unfortunately, space technology is very expensive, so extra-atmospheric observatories are created either by the richest countries, or by several countries in cooperation with each other. Initially, certain groups of scientists were engaged in the development of instruments for astronomical satellites and the analysis of the data obtained. But as the productivity of space telescopes has grown, a system of cooperation has developed similar to that adopted in national observatories. For example, the Hubble Space Telescope (USA) is available to any astronomer in the world: applications for observations are accepted and evaluated, the most worthy of them are carried out and the results are sent to the scientist for analysis. This activity is organized by the Space Telescope Science Institute.
- (new lat. observatorium, from observare to observe). Building for physical and astronomical observations. Dictionary of foreign words included in the Russian language. Chudinov A.N., 1910. OBSERVATORY building serving for astronomical, ... ... Dictionary of foreign words of the Russian language

Astronomical observatories (in astronomy). Description of observatories in antiquity and in the modern world.

An astronomical observatory is a scientific institution designed to observe celestial bodies. It is built on high place from which you can look anywhere. All observatories are necessarily equipped with telescopes and similar equipment for astronomical and geophysical observations.

1. Astronomical "observatories" in antiquity.
Since ancient times, for astronomical observations, people have been located on hills or high terrain. Pyramids also served for observation.

Not far from the fortress of Karnak, which is located in the city of Luxor, there is a sanctuary of Ra - Gorakhte. On the day of the winter solstice, the sunrise was observed from there.
The oldest prototype of an astronomical observatory is the famous Stonehenge. There is an assumption that in a number of parameters it corresponded to sunrises on the days of the summer solstice.
2. The first astronomical observatories.
Already in 1425, one of the first observatories was completed near Samarkand. It was unique, as there was nothing like it anywhere else.
Later, the Danish king took an island near Sweden to create an astronomical observatory. Two observatories were built. And for 21 years, the activity of the king continued on the island, during which people learned more and more about what the Universe is.
3. Observatories of Europe and Russia.
Soon, observatories began to be rapidly created in Europe. One of the first was the observatory in Copenhagen.
One of the most majestic observatories of that time was built in Paris. The best scientists work there.
The Royal Greenwich Observatory owes its popularity to the fact that the "Greenwich meridian" passes through the axis of the transit instrument. It was founded by order of the ruler Charles II. The construction was justified by the need to measure the longitude of a place when navigating.
After the construction of the Paris and Greenwich observatories, state observatories began to be created in numerous other European countries. More than 100 observatories begin to operate. They operate in almost every educational institution, and the number of private observatories is increasing.
Among the first, the observatory of the St. Petersburg Academy of Sciences was built. In 1690, on the Northern Dvina, near Arkhangelsk, the fundamental astronomical observatory in Russia was created. In 1839, another observatory, Pulkovo, was opened. The Pulkovo observatory was and is of the greatest importance compared to others. The Astronomical Observatory of the St. Petersburg Academy of Sciences was closed, and its numerous instruments and instruments were moved to Pulkovo.
The beginning of a new stage in the development of astronomical science refers to the establishment of the Academy of Sciences.
With the collapse of the USSR, the costs of research development are reduced. Because of this, non-state-affiliated observatories equipped with professional-level technology are beginning to appear in the country.

OBSERVATORY, an institution for the production of astronomical or geophysical (magnetometric, meteorological and seismic) observations; hence the division of observatories into astronomical, magnetometric, meteorological and seismic.

astronomical observatory

According to their purpose, astronomical observatories can be divided into two main types: astrometric and astrophysical observatories. Astrometric observatories are engaged in determining the exact positions of stars and other luminaries for different purposes and, depending on this, with different tools and methods. Astrophysical observatories study various physical properties celestial bodies, such as temperature, brightness, density, as well as other properties that require physical methods of study, such as the movement of stars along the line of sight, the diameters of stars determined by interference, etc. Many large observatories have mixed goals, but there are observatories and narrower purposes, for example, for observing the variability of geographic latitude, for searching for small planets, observing variable stars, etc.

Observatory location must satisfy a number of requirements, which include: 1) the complete absence of shaking caused by the proximity of railways, traffic or factories, 2) the highest purity and transparency of the air - the absence of dust, smoke, fog, 3) the absence of sky illumination caused by the proximity of the city , factories, railway stations etc., 4) the calmness of the air at night, 5) a sufficiently open horizon. Conditions 1, 2, 3, and partly 5 force observatories to be moved outside the city, often even to considerable heights above sea level, creating mountain observatories. Condition 4 depends on a number of factors, partly general climatic (winds, humidity), partly local. In any case, it forces one to avoid places with strong air currents, for example, arising from the strong heating of the soil by the sun, sharp fluctuations in temperature and humidity. The most favorable are areas covered with a uniform vegetation cover, with a dry climate, at a sufficient height above sea level. Modern observatories usually consist of separate pavilions located in the middle of a park or scattered across a meadow, in which instruments are installed (Fig. 1).

To the side there are laboratories - rooms for measuring and computing work, for studying photographic plates and for performing various experiments (for example, for studying the radiation of a completely black body, as a standard for determining the temperature of stars), a mechanical workshop, a library and living quarters. In one of the buildings there is a cellar for the clock. If the observatory is not connected to the electrical mains, then its own power plant is arranged.

Instrumental equipment of observatories varies greatly depending on the destination. To determine the right ascensions and declinations of the luminaries, a meridian circle is used, which simultaneously gives both coordinates. At some observatories, following the example of the Pulkovo observatory, two different instruments are used for this purpose: a transit instrument and a vertical circle, which make it possible to determine the mentioned coordinates separately. The most observations are divided into fundamental and relative. The first consists in the independent derivation of an independent system of right ascensions and declinations with the determination of the position of the vernal equinox and the equator. The second consists in linking observed stars, usually located in a narrow declination zone (hence the term: zone observations), to reference stars, the position of which is known from fundamental observations. For relative observations, photography is now increasingly being used, and this area of ​​\u200b\u200bthe sky is taken with special tubes with a camera (astrographs) with a sufficiently large focal length (usually 2-3.4 m). Relative determination of the position of objects close to each other, for example, binary stars, minor planets and comets, in relation to nearby stars, satellites of planets relative to the planet itself, determination of annual parallaxes - is carried out using equatorials both visually - using an ocular micrometer, and photographic, in which the eyepiece is replaced by a photographic plate. For this purpose, the largest instruments are used, with lenses 0 to 1 m. The variability of latitude is studied mainly with the help of zenith telescopes.

The main observations of an astrophysical nature are photometric, including colorimetry, i.e., determining the color of stars, and spectroscopic. The former are produced by means of photometers mounted as independent instruments or, more often, attached to a refractor or reflector. For spectral observations, slit spectrographs are used, which are attached to the largest reflectors (with a mirror of 0 to 2.5 m) or, in obsolete cases, to large refractors. The resulting photographs of the spectra are used for various purposes, such as: determination of radial velocities, spectroscopic parallaxes, temperature. For a general classification of stellar spectra, more modest tools can be used - the so-called. prismatic chambers, consisting of a fast, short-focus photographic camera with a prism in front of the lens, giving the spectra of many stars on one plate, but with low dispersion. For spectral studies of the sun, as well as stars, some observatories use the so-called. tower telescopes representing known benefits. They consist of a tower (up to 45 m high), on top of which there is a celestial, which sends the rays of the luminary vertically downwards; a lens is placed slightly below the coelite, through which the rays pass, gathering in focus at ground level, where they enter a vertical or horizontal spectrograph, which is under constant temperature conditions.

The tools mentioned above are mounted on solid stone pillars with a deep and large foundation, isolated from the rest of the building so that vibrations are not transmitted. Refractors and reflectors are placed in round towers (Fig. 2), covered with a hemispherical rotating dome with a drop-down hatch through which observation takes place.

For refractors, the floor in the tower is made elevating, so that the observer can comfortably reach the ocular end of the telescope at any inclination of the latter to the horizon. In reflector towers, instead of a lifting floor, stairs and small lifting platforms are usually used. The towers of large reflectors must have such a device that would provide good thermal insulation during the day against heating and sufficient ventilation at night, with the dome open. Instruments intended for observation in one specific vertical - a meridian circle, a passage instrument, and a partly vertical circle - are installed in pavilions made of corrugated iron (Fig. 3), having the shape of a lying half-cylinder. By opening wide hatches or rolling back the walls, a wide gap is formed in the plane of the meridian or the first vertical, depending on the installation of the instrument, allowing observations to be made.

The device of the pavilion should provide for good ventilation, because when observing the air temperature inside the pavilion should be equal to the outside temperature, which eliminates the incorrect refraction of the line of sight, called hall refraction(Saalrefaction). With passage instruments and meridian circles, worlds are often arranged, which are solid marks installed in the meridian plane at some distance from the instrument.

Observatories serving time, as well as making fundamental determinations of right ascensions, require a large clock setting. The clock is placed in the basement, under conditions of constant temperature. Distribution boards and chronographs are placed in a special room for comparing hours. A radio station is also installed here. If the observatory itself sends time signals, then an installation for automatic sending of signals is also required; transmission is made through one of the powerful transmission radio stations.

In addition to permanently functioning observatories, temporary observatories and stations are sometimes set up, designed either to observe short-term phenomena, mainly solar eclipses (previously also the transits of Venus across the disk of the sun), or to perform certain work, after which such an observatory is again closed. Thus, some European and especially North American observatories opened temporary - for several years - branches in the southern hemisphere to observe the southern sky in order to compile positional, photometric or spectroscopic catalogs of southern stars using the same methods and tools that were used for the same purpose at the main observatory. in the northern hemisphere. The total number of currently operating astronomical observatories reaches 300. Some data, namely: location, main instruments and main works regarding the main modern observatories are given in the table.

magnetic observatory

A magnetic observatory is a station conducting regular observations of geomagnetic elements. It is a reference point for geomagnetic surveys of the area adjacent to it. The material provided by the magnetic observatory is fundamental in the study of magnetic life. the globe. The work of a magnetic observatory can be divided into the following cycles: 1) the study of temporal variations in the elements of terrestrial magnetism, 2) their regular measurements in absolute measure, 3) the study and study of geomagnetic instruments used in magnetic surveys, 4) special research work in areas of geomagnetic phenomena.

To carry out these works, the magnetic observatory has a set of normal geomagnetic instruments for measuring the elements of terrestrial magnetism in absolute terms: magnetic theodolite and inclinator, usually of the induction type, as more advanced. These devices b. compared with standard instruments available in each country (in the USSR they are stored at the Slutsk Magnetic Observatory), in turn compared with the international standard in Washington. To study temporal variations of the terrestrial magnetic field, the observatory has at its disposal one or two sets of variational instruments - variometers D, H and Z - providing continuous recording of changes in the elements of terrestrial magnetism over time. The principle of operation of the above devices - see terrestrial magnetism. The constructions of the most common of them are described below.

A magnetic theodolite for absolute measurements of H is shown in Fig. 4 and 5. Here A is a horizontal circle, readings from which are taken using microscopes B; I - tube for observations by the method of autocollimation; C - a house for magnet m, D - a locking device fixed at the base of the tube, inside which a thread passes, supporting magnet m. In the upper part of this tube there is a head F, with which the thread is fastened. Deflecting (auxiliary) magnets are placed on the M 1 and M 2 lagers; the orientation of the magnet on them is determined by special circles with readings using microscopes a and b. Observations of declination are carried out using the same theodolite, or a special declinator is installed, the design of which is in general terms the same as that of the described device, but without devices for deviations. To determine the location of true north on the azimuthal circle, a specially set measure is used, the true azimuth of which is determined using astronomical or geodetic measurements.

The earth inductor (inclinator) for determining the inclination is shown in Fig. 6 and 7. A double coil S can rotate about an axis lying on bearings mounted in a ring R. The position of the axis of rotation of the coil is determined by a vertical circle V using microscopes M, M. H is a horizontal circle that serves to set the axis of the coil in the plane of the magnetic meridian, K - a switch for converting alternating current, obtained by rotating the coil, into direct current. From the terminals of this commutator, current is supplied to a sensitive galvanometer with a satazated magnetic system.

Variometer H is shown in Fig. 8. Inside a small chamber, a magnet M is suspended on a quartz thread or on a bifilar. The upper attachment point of the thread is at the top of the suspension tube and is connected to the head T, which can rotate about the vertical axis.

A mirror S is inseparably attached to the magnet, onto which a beam of light from the illuminator of the recording apparatus falls. Next to the mirror, a fixed mirror B is fixed, the purpose of which is to draw a base line on the magnetogram. L is a lens that gives an image of the illuminator slit on the drum of the recording apparatus. A cylindrical lens is installed in front of the drum, reducing this image to a point. That. recording on photographic paper screwed onto the drum is made by moving along the generatrix of the drum a light spot from a beam of light reflected from the mirror S. The design of the variometer B is the same as that of the described device, except for the orientation of the magnet M with respect to the mirror S.

Variometer Z (Fig. 9) essentially consists of a magnetic system oscillating about a horizontal axis. The system is enclosed inside the chamber 1, which has an opening in its front part, closed by a lens 2. The oscillations of the magnetic system are recorded by the recorder thanks to a mirror, which is attached to the system. To build the baseline, a fixed mirror is used, located next to the movable one. The general arrangement of variometers during observations is shown in Fig. 10.

Here R is the recording apparatus, U is its clockwork, which rotates the drum W with light-sensitive paper, l is a cylindrical lens, S is the illuminator, H, D, Z are variometers for the corresponding elements of terrestrial magnetism. In the Z variometer, the letters L, M, and t denote, respectively, the lens, the mirror connected to the magnetic system, and the mirror attached to the device for recording temperatures. Depending on the special tasks in which the observatory takes part, its further equipment is already of a special nature. Reliable operation of geomagnetic instruments requires special conditions in the sense of the absence of disturbing magnetic fields, temperature constancy, etc.; therefore, magnetic observatories are taken out far from the city with its electrical installations and arranged in such a way as to guarantee the desired degree of temperature constancy. For this, pavilions where magnetic measurements are made are usually built with double walls and the heating system is located along the corridor formed by the outer and inner walls of the building. In order to exclude the mutual influence of variational instruments on normal ones, both are usually installed in different pavilions, somewhat distant from each other. When constructing such buildings, b. special attention was paid to the fact that there were no iron masses inside them and nearby, especially moving ones. With regard to electrical wiring, b. conditions are met that guarantee the absence of magnetic fields of electric current (bifilar wiring). The proximity of structures that create mechanical shaking is unacceptable.

Since the magnetic observatory is the main point for the study of magnetic life: the earth, requirement b. or m. their uniform distribution over the entire surface of the globe. At present, this requirement is only approximately met. The table below, presenting the list of magnetic observatories, gives an idea of ​​the extent to which this requirement has been met. In the table, italics indicate the average annual change in the element of terrestrial magnetism, due to the secular course.

The richest material collected by magnetic observatories consists in the study of temporal variations of geomagnetic elements. This includes the daily, annual and secular course, as well as those sudden changes in the earth's magnetic field, which are called magnetic storms. As a result of the study of diurnal variations, it became possible to distinguish in them the influence of the position of the sun and moon in relation to the place of observation and to establish the role of these two cosmic bodies in the diurnal variations of geomagnetic elements. The main cause of variation is the sun; the influence of the moon does not exceed 1/15 of the action of the first luminary. The amplitude of diurnal fluctuations on average has a value of the order of 50 γ (γ = 0.00001 gauss, see Terrestrial Magnetism), i.e., about 1/1000 of the total stress; it varies depending on the geographical latitude of the place of observation and strongly depends on the time of year. As a rule, the amplitude of diurnal variations in summer is greater than in winter. The study of the time distribution of magnetic storms led to the ascertaining of their connection with the activity of the sun. The number of storms and their intensity coincide in time with the number of sunspots. This circumstance allowed Stormer to create a theory explaining the occurrence of magnetic storms by the penetration into the upper layers of our atmosphere of electric charges emitted by the sun during periods of its greatest activity, and by the parallel formation of a ring of moving electrons at a considerable height, almost outside the atmosphere, in the plane of the earth's equator.

meteorological observatory

observatory meteorological, the highest scientific institution for the study of issues related to the physical life of the earth in the broadest sense. These observatories are now dealing not only with purely meteorological and climatological questions and the weather service, but also include in the scope of their tasks the questions of terrestrial magnetism, atmospheric electricity and atmospheric optics; some observatories even conduct seismic observations. Therefore, such observatories have a broader name - geophysical observatories or institutes.

Observatories' own observations in the field of meteorology are meant to provide strictly scientific material of observations made on meteorological elements, necessary for the purposes of climatology, weather service and satisfying a number of practical requests based on records of recorders with continuous recording of all changes in the course of meteorological elements. Direct observations at certain urgent hours are made on such elements as air pressure (see Barometer), its temperature and humidity (see Hygrometer), wind direction and speed, sunshine, precipitation and evaporation, snow cover, soil temperature and other atmospheric phenomena according to the program of ordinary meteorology, stations of the 2nd category. In addition to these program observations, control observations are made at meteorological observatories, and methodological studies are also carried out, expressed in the establishment and testing of new methods of observation of phenomena, as already partly studied; and not studied at all. Observatory observations must be long-term in order to be able to draw a number of conclusions from them in order to obtain with sufficient accuracy the average "normal" values, to determine the magnitude of non-periodic fluctuations inherent in this place observations, and to determine patterns in the course of these phenomena over time.

In addition to making their own meteorological observations, one of the major tasks of the observatories is to study the entire country as a whole or its individual regions in physical terms and ch. arr. in terms of climate. The observational material coming from the network of meteorological stations to the observatory is subjected here to a detailed study, control and thorough verification in order to select the most benign observations that can already be used for further development. Initial findings from this verified material are published in the observatory's publications. Such publications on the network of former stations. Russia and the USSR cover observations starting from 1849. These publications publish ch. arr. conclusions from observations, and only for a small number of stations, observations are printed in full.

The rest of the processed and verified material is stored in the archive of the observatory. As a result of deep and careful study From time to time various monographs appear on these materials, either characterizing the processing technique or concerning the development of individual meteorological elements.

One of the specific features of the activities of the observatories is a special service for forecasting and warning about the state of the weather. At present, this service has been separated from the Main Geophysical Observatory in the form of an independent institute - the Central Weather Bureau. To show the development and achievements of our weather service, below are data on the number of telegrams received by the Weather Bureau per day since 1917.

At present, the Central Weather Bureau receives up to 700 internal telegrams alone, apart from reports. In addition, large-scale work is being carried out here to improve weather forecasting methods. As for the degree of success of short-term predictions, it is determined at 80-85%. In addition to short-term forecasts, methods have now been developed and long-term predictions of the general nature of the weather for the coming season or for short periods, or detailed predictions on individual issues (opening and freezing of rivers, floods, thunderstorms, snowstorms, hail, etc.) are being made.

In order for the observations made at the stations of the meteorological network to be comparable with each other, it is necessary that the instruments used to make these observations be compared with the "normal" standards adopted at international congresses. The task of checking instruments is solved by a special department of the observatory; at all stations of the network, only instruments tested at the observatory and provided with special certificates are used, giving either corrections or constants for the corresponding instruments under given observation conditions. In addition, for the same purposes of comparability of the results of direct meteorological observations at stations and the observatory, these observations must be made within strictly defined periods and according to a specific program. In view of this, the observatory issues special instructions for making observations, revised from time to time on the basis of experiments, the progress of science, and in accordance with the decisions of international congresses and conferences. The observatory, on the other hand, calculates and publishes special tables for processing meteorological observations made at the stations.

In addition to meteorological research, a number of observatories also carry out actinometric studies and systematic observations of solar radiation intensity, diffuse radiation, and the earth's own radiation. In this regard, the observatory in Slutsk (former Pavlovsk) is well-deservedly known, where a large number of instruments have been designed both for direct measurements and for continuous automatic recording of changes in various radiation elements (actinographs), and these instruments were installed here for operation earlier than at observatories in other countries. In some cases, studies are underway to study the energy in individual parts of the spectrum in addition to the integral radiation. Questions connected with the polarization of light are also the subject of a special study of observatories.

Scientific flights in balloons and free balloons, carried out repeatedly to make direct observations of the state of meteorological elements in the free atmosphere, although they provided a number of very valuable data for understanding the life of the atmosphere and the laws that govern it, nevertheless, these flights had only a very limited application. in everyday life due to the significant costs associated with them, as well as the difficulty of reaching great heights. The successes of aviation made persistent demands for ascertaining the state of meteorological elements and Ch. arr. direction and speed of the wind at different heights in the free atmosphere, and so on. put forward the importance of aerological research. Special institutes were organized, special methods were developed for raising recorders of various designs, which are raised to a height on kites or with the help of special rubber balloons filled with hydrogen. The records of such recorders provide information on the state of pressure, temperature and humidity, as well as on the speed of air movement and direction at various altitudes in the atmosphere. In the case when only information about the wind in different layers is required, observations are made on small pilot balloons freely released from the observation point. In view of the great importance of such observations for the purposes of air transport, the observatory organizes a whole network of aerological points; the processing of the results of the observations made, as well as the solution of a number of problems of theoretical and practical importance concerning the motion of the atmosphere, are carried out at observatories. Systematic observations at high-mountain observatories also provide material for understanding the laws of atmospheric circulation. In addition, such high-mountain observatories are important in matters relating to the feeding of rivers originating from glaciers and related irrigation issues, which is important in semi-desert climates, for example, in Central Asia.

Turning to observations on the elements of atmospheric electricity, carried out at observatories, it is necessary to indicate that they are directly related to radioactivity and, moreover, are of certain importance in the development of agricultural production. cultures. The purpose of these observations is to measure the radioactivity and degree of ionization of the air, as well as to determine the electrical state of the precipitation that falls on the ground. Any disturbances that occur in the electric field of the earth cause disturbances in wireless, and sometimes even in wire communication. Observatories located in coastal areas include in their program of work and research the study of hydrology of the sea, observations and forecasts of the state of the sea, which is of direct importance for the purposes of maritime transport.

In addition to obtaining observational material, processing it and possible conclusions, in many cases it seems necessary to subject the phenomena observed in nature to experimental and theoretical study. From this follow the tasks of laboratory and mathematical research carried out by observatories. Under the conditions of a laboratory experiment, it is sometimes possible to reproduce one or another atmospheric phenomenon, to study in a comprehensive manner the conditions for its occurrence and its causes. In this regard, one can point to the work carried out at the Main Geophysical Observatory, for example, on studying the phenomenon of bottom ice and determining measures to combat this phenomenon. In the same way, the problem of the rate of cooling of a heated body in an air stream was studied in the laboratory of the observatory, which is directly related to the solution of the problem of heat transfer in the atmosphere. Finally, mathematical analysis finds wide application in solving a number of problems related to the processes and various phenomena that take place in atmospheric conditions, for example, circulation, turbulent motion, etc. In conclusion, we give a list of observatories located in the USSR. In the first place it is necessary to put the Main Geophysical Observatory (Leningrad), founded in 1849; next to it as its suburban branch is an observatory in Slutsk. These institutions carry out tasks on the scale of the entire Union. In addition to them, a number of observatories with functions of republican, regional or regional significance: the Geophysical Institute in Moscow, the Central Asian Meteorological Institute in Tashkent, the Geophysical Observatory in Tiflis, Kharkov, Kiev, Sverdlovsk, Irkutsk and Vladivostok, organized by the Geophysical Institutes in Saratov for the Lower Volga region and in Novosibirsk for western Siberia. There are a number of observatories on the seas - in Arkhangelsk and a newly organized observatory in Aleksandrovsk for the northern basin, in Kronstadt - for the Baltic Sea, in Sevastopol and Feodosia - for the Black and Seas of Azov, in Baku - for the Caspian Sea and in Vladivostok - for Pacific Ocean. A number of former universities also have observatories with major works in the field of meteorology and geophysics in general - Kazan, Odessa, Kiev, Tomsk. All these observatories not only conduct observations at one point, but also organize expeditionary research, either independent or complex, on various problems and departments of geophysics, thereby greatly contributing to the study of the productive forces of the USSR.

seismic observatory

seismic observatory serves to register and study earthquakes. The main instrument in the practice of measuring earthquakes is a seismograph, which automatically records any shaking that occurs in a certain plane. Therefore, a series of three instruments, two of which are horizontal pendulums that capture and record those components of motion or velocity that occur in the direction of the meridian (NS) and parallel (EW), and the third is a vertical pendulum for recording vertical displacements, is necessary and sufficient. to resolve the issue of the location of the epicentral region and the nature of the earthquake that occurred. Unfortunately, most seismic stations are only equipped with instruments for measuring horizontal components. The general organizational structure of the seismic service in the USSR is as follows. The whole thing is headed by the Seismic Institute, which is part of the USSR Academy of Sciences in Leningrad. The latter directs the scientific and practical activities of observation posts - seismic observatories and various stations located in certain regions of the country and making observations according to a specific program. The Central Seismic Observatory in Pulkovo, on the one hand, is engaged in the production of regular and continuous observations of all three components of the movement of the earth's crust through several series of recording instruments, on the other hand, it performs a comparative study of apparatus and methods for processing seismograms. In addition, on the basis of their own study and experience, other stations of the seismic network are instructed here. In accordance with such an important role that this observatory plays in the study of the country in a seismic sense, it has a specially arranged underground pavilion so that all external effects - temperature changes, building vibrations under the influence of wind blows, etc. - are eliminated. One of the halls of this pavilion is isolated from the walls and floor of the common building and contains the most important series of instruments of very high sensitivity. Instruments designed by Academician B. B. Golitsyn are of great importance in the practice of modern seismometry. In these devices, the movement of pendulums can be registered not mechanically, but with the help of the so-called galvanometric registration, at which there is a change in the electrical state in the coil moving together with the pendulum of the seismograph in the magnetic field of a strong magnet. By means of wires, each coil is connected to a galvanometer, the needle of which oscillates along with the movement of the pendulum. A mirror attached to a galvanometer pointer makes it possible to follow the ongoing changes in the instrument, either directly or by means of photographic recording. That. there is no need to enter the hall with instruments and thereby disturb the equilibrium in the instruments with air currents. With this setup, the instruments can have a very high sensitivity. In addition to those indicated, seismographs with mechanical registration. Their design is more crude, the sensitivity is much lower, and with the help of these devices it is possible to control, and most importantly, restore the recordings of high-sensitivity devices in case of various kinds of failures. At the central observatory, in addition to ongoing work, numerous special studies of scientific and applied significance are also carried out.

Observatories or stations of the 1st category designed to record distant earthquakes. They are equipped with instruments of sufficiently high sensitivity, and in most cases they are equipped with one set of instruments for the three components of the earth's motion. Synchronous recording of the readings of these instruments makes it possible to determine the angle of exit of seismic rays, and from the records of a vertical pendulum it is possible to decide on the nature of the wave, i.e., to determine when a compression or rarefaction wave approaches. Some of these stations still have devices for mechanical recording, that is, less sensitive ones. A number of stations, in addition to general ones, deal with local issues of significant practical importance, for example, in Makeevka (Donbass), according to instrument records, one can find a connection between seismic phenomena and firedamp emissions; installations in Baku make it possible to determine the effect of seismic phenomena on the regime of oil sources, etc. All these observatories publish independent bulletins, in which, in addition to general information about the position of the station and phase, secondary maxima, etc. In addition, data are reported on the proper displacements of the soil during earthquakes.

Finally observation seismic points of the 2nd category designed to record earthquakes that are not particularly distant or even local. In view of this, these stations are located Ch. arr. in seismic areas, such as the Caucasus, Turkestan, Altai, Baikal, the Kamchatka Peninsula and Sakhalin Island in our Union. These stations are equipped with heavy pendulums with mechanical registration, have special semi-underground pavilions for installations; they determine the moments of the onset of primary, secondary and long waves, as well as the distance to the epicenter. All these seismic observatories are also in the service of time, since instrumental observations are estimated with an accuracy of a few seconds.

Of the other problems dealt with by the special observatory, we point to the study of lunar-solar attraction, i.e., tidal movements of the earth's crust, analogous to the phenomena of ebb and flow observed in the sea. For these observations, among other things, a special observatory was built inside a hill near Tomsk, and 4 horizontal Zellner system pendulums were installed here in 4 different azimuths. With the help of special seismic installations, observations were made of the oscillations of the walls of buildings under the influence of diesel engines, observations of the oscillations of the abutments of bridges, especially railway ones, during the movement of trains over them, observations of the regime of mineral springs, etc. Recently, seismic observatories have undertaken special expeditionary observations in in order to study the location and distribution of underground layers, which is of great importance in the search for minerals, especially if these observations are accompanied by gravimetric work. Finally, an important expeditionary work of seismic observatories is the production of high-precision levels in areas subject to significant seismic events, because repeated work in these areas makes it possible to accurately determine the magnitude of the horizontal and vertical displacements that occurred as a result of this or that earthquake, and to make a forecast for further displacements. and earthquake events.

Details Category: The work of astronomers Posted on 10/11/2012 17:13 Views: 8741

An astronomical observatory is a research institution in which systematic observations of celestial bodies and phenomena are carried out.

Usually the observatory is built on an elevated area, where a good outlook opens up. The observatory is equipped with observation instruments: optical and radio telescopes, instruments for processing the results of observations: astrographs, spectrographs, astrophotometers and other devices for characterizing celestial bodies.

From the history of the observatory

It is difficult even to name the time when the first observatories appeared. Of course, these were primitive structures, but nevertheless, observations of heavenly bodies were carried out in them. The most ancient observatories are located in Assyria, Babylon, China, Egypt, Persia, India, Mexico, Peru and other states. The ancient priests, in fact, were the first astronomers, because they observed the starry sky.
An observatory dating back to the Stone Age. It is located near London. This building was both a temple and a place for astronomical observations - the interpretation of Stonehenge as a grand observatory of the Stone Age belongs to J. Hawkins and J. White. Assumptions that this is the oldest observatory are based on the fact that its stone slabs are installed in a certain order. It is well known that Stonehenge was a sacred place of the Druids - representatives of the priestly caste of the ancient Celts. Druids were very well versed in astronomy, for example, in the structure and movement of stars, the size of the Earth and planets, and various astronomical phenomena. About where they got this knowledge, science is not known. It is believed that they inherited them from the true builders of Stonehenge and, thanks to this, they had great power and influence.

Another ancient observatory was found on the territory of Armenia, built about 5 thousand years ago.
In the 15th century in Samarkand, the great astronomer Ulugbek built an outstanding observatory for its time, in which the main instrument was a huge quadrant for measuring the angular distances of stars and other bodies (read about this on our website: http://website/index.php/earth/rabota-astrnom/10-etapi- astronimii/12-sredneverovaya-astronomiya).
The first observatory in the modern sense of the word was the famous museum in Alexandria arranged by Ptolemy II Philadelphus. Aristillus, Timocharis, Hipparchus, Aristarchus, Eratosthenes, Geminus, Ptolemy and others achieved unprecedented results here. Here, for the first time, instruments with divided circles began to be used. Aristarchus installed a copper circle in the plane of the equator and with its help observed directly the times of the passage of the Sun through the equinoxes. Hipparchus invented the astrolabe (an astronomical instrument based on the principle of stereographic projection) with two mutually perpendicular circles and diopters for observations. Ptolemy introduced quadrants and installed them with a plumb line. The transition from full circles to quadrants was, in fact, a step backwards, but the authority of Ptolemy kept quadrants on observatories until the time of Römer, who proved that full circles made observations more accurately; however, the quadrants were completely abandoned only at the beginning of the 19th century.

The first observatories of the modern type began to be built in Europe after the invention of the telescope in the 17th century. The first large state observatory - parisian. It was built in 1667. Along with quadrants and other instruments of ancient astronomy, large refracting telescopes were already used here. In 1675 opened Greenwich Royal Observatory in England, on the outskirts of London.
There are more than 500 observatories in the world.

Russian observatories

The first observatory in Russia was the private observatory of A.A. Lyubimov in Kholmogory, Arkhangelsk region, opened in 1692. In 1701, by decree of Peter I, an observatory was created at the Navigation School in Moscow. In 1839, the Pulkovo Observatory near St. Petersburg was founded, equipped with the most advanced instruments, which made it possible to obtain high-precision results. For this, the Pulkovo Observatory was named the astronomical capital of the world. Now there are more than 20 astronomical observatories in Russia, among them the Main (Pulkovo) Astronomical Observatory of the Academy of Sciences is the leading one.

Observatories of the world

Among foreign observatories, the largest are Greenwich (Great Britain), Harvard and Mount Palomar (USA), Potsdam (Germany), Krakow (Poland), Byurakan (Armenia), Vienna (Austria), Crimean (Ukraine), etc. Observatories of various countries share the results of observations and research, often work on the same program to develop the most accurate data.

The device of observatories

For modern observatories, a characteristic view is the building of a cylindrical or polyhedral shape. These are towers in which telescopes are installed. Modern observatories are equipped with optical telescopes located in closed domed buildings or radio telescopes. The light radiation collected by telescopes is recorded by photographic or photoelectric methods and analyzed to obtain information about distant astronomical objects. Observatories are usually located far from cities, in climatic zones with little cloud cover and, if possible, on high plateaus, where atmospheric turbulence is negligible and infrared radiation absorbed by the lower atmosphere can be studied.

Types of observatories

There are specialized observatories that work according to a narrow scientific program: radio astronomy, mountain stations for observing the Sun; some observatories are associated with observations made by astronauts from spacecraft and orbital stations.
Most of the infrared and ultraviolet range, as well as X-rays and gamma rays of cosmic origin, are inaccessible to observations from the Earth's surface. In order to study the Universe in these rays, it is necessary to take observation instruments into space. Until recently, extra-atmospheric astronomy was unavailable. Now it has become a rapidly developing branch of science. The results obtained with space telescopes, without the slightest exaggeration, turned over many of our ideas about the Universe.
The modern space telescope is a unique set of instruments developed and operated by several countries for many years. Thousands of astronomers from all over the world take part in observations at modern orbital observatories.

The picture shows the project of the largest infrared optical telescope at the European Southern Observatory with a height of 40 m.

The successful operation of a space observatory requires the joint efforts of a variety of specialists. Space engineers prepare the telescope for launch, put it into orbit, monitor the power supply of all instruments and their normal functioning. Each object can be observed for several hours, so it is especially important to keep the orientation of the satellite orbiting the Earth in the same direction so that the axis of the telescope remains aimed directly at the object.

infrared observatories

To carry out infrared observations, a rather large load has to be sent into space: the telescope itself, devices for processing and transmitting information, a cooler that should protect the IR receiver from background radiation - infrared quanta emitted by the telescope itself. Therefore, in the entire history of space flight, very few infrared telescopes have operated in space. The first infrared observatory was launched in January 1983 as part of the joint American-European project IRAS. In November 1995, the European Space Agency launched the ISO infrared observatory into low Earth orbit. It has a telescope with the same mirror diameter as IRAS, but more sensitive detectors are used to detect radiation. A wider range of the infrared spectrum is available for ISO observations. Currently, several more projects of space infrared telescopes are being developed, which will be launched in the coming years.
Do not do without infrared equipment and interplanetary stations.

ultraviolet observatories

The ultraviolet radiation of the Sun and stars is almost completely absorbed by the ozone layer of our atmosphere, so UV quanta can only be recorded in the upper layers of the atmosphere and beyond.
For the first time, an ultraviolet reflecting telescope with a mirror diameter (SO cm) and a special ultraviolet spectrometer were launched into space on the joint American-European satellite Copernicus, launched in August 1972. Observations on it were carried out until 1981.
Currently, work is underway in Russia to prepare for the launch of a new ultraviolet telescope "Spektr-UV" with a mirror diameter of 170 cm. observations with ground-based instruments in the ultraviolet (UV) part of the electromagnetic spectrum: 100-320 nm.
The project is headed by Russia and included in the Federal Space Program for 2006-2015. Russia, Spain, Germany and Ukraine are currently participating in the project. Kazakhstan and India are also showing interest in participating in the project. The Institute of Astronomy of the Russian Academy of Sciences is the lead scientific organization of the project. The head organization for the rocket and space complex is the NPO named after. S.A. Lavochkin.
The main instrument of the observatory is being created in Russia - a space telescope with a primary mirror 170 cm in diameter. The telescope will be equipped with high and low resolution spectrographs, a long slit spectrograph, as well as cameras for high-quality imaging in the UV and optical regions of the spectrum.
In terms of capabilities, the VKO-UV project is comparable to the American Hubble Space Telescope (HST) and even surpasses it in spectroscopy.
WSO-UV will open up new opportunities for planetary research, stellar, extragalactic astrophysics and cosmology. The launch of the observatory is scheduled for 2016.

X-ray observatories

X-rays convey information to us about powerful cosmic processes associated with extreme physical conditions. The high energy of X-ray and gamma quanta makes it possible to register them "by the piece", with an accurate indication of the time of registration. X-ray detectors are relatively easy to manufacture and light in weight. Therefore, they were used for observations in the upper atmosphere and beyond with the help of high-altitude rockets even before the first launches of artificial earth satellites. X-ray telescopes were installed at many orbital stations and interplanetary spacecraft. In total, about a hundred such telescopes have been in near-Earth space.

gamma-ray observatories

Gamma radiation is closely adjacent to X-rays, so similar methods are used to register it. Very often, telescopes launched into near-Earth orbits simultaneously investigate both X-ray and gamma-ray sources. Gamma rays convey to us information about the processes occurring inside atomic nuclei, and about the transformations of elementary particles in space.
The first observations of cosmic gamma sources were classified. In the late 60s - early 70s. The United States launched four military satellites of the Vela series. The equipment of these satellites was developed to detect bursts of hard X-ray and gamma radiation that occur during nuclear explosions. However, it turned out that most of the recorded bursts are not associated with military tests, and their sources are located not on Earth, but in space. Thus, one of the most mysterious phenomena in the Universe was discovered - gamma-ray flashes, which are single powerful flashes of hard radiation. Although the first cosmic gamma-ray bursts were recorded as early as 1969, information about them was published only four years later.

An observatory is a scientific institution in which employees - scientists of various specialties - observe natural phenomena, analyze observations, and continue to study what happens in nature on their basis.


Astronomical observatories are especially common: we usually imagine them when we hear this word. They explore stars, planets, large star clusters, and other space objects.

But there are other types of these institutions:

- geophysical - to study the atmosphere, the aurora, the Earth's magnetosphere, the properties of rocks, the state of the earth's crust in seismically active regions and other similar issues and objects;

- auroral - to study the aurora borealis;

- seismic - for continuous and detailed registration of all fluctuations of the earth's crust and their study;

- meteorological - to study weather conditions and identify weather patterns;

- cosmic ray observatories and a number of others.

Where are observatories built?

Observatories are built in those areas that give scientists the maximum material for research.


Meteorological - in all corners of the Earth; astronomical - in the mountains (where the air is clean, dry, not "blinded" by city lighting), radio observatories - at the bottom of deep valleys, inaccessible to artificial radio interference.

Astronomical observatories

Astronomical - the most ancient type of observatories. Astronomers in ancient times were priests, they kept a calendar, studied the movement of the Sun in the sky, were engaged in predicting events, the fate of people, depending on the juxtaposition of celestial bodies. These were astrologers - people who were afraid of even the most ferocious rulers.

Ancient observatories were usually located in the upper rooms of the towers. The tools were a straight bar equipped with a sliding sight.

The great astronomer of antiquity was Ptolemy, who collected in the Library of Alexandria a huge number of astronomical evidence, records, formed a catalog of positions and brightness for 1022 stars; invented the mathematical theory of the movement of the planets and compiled tables of motion - scientists used these tables for more than 1,000 years!

In the Middle Ages, observatories were especially actively built in the East. The giant Samarkand observatory is known, where Ulugbek, a descendant of the legendary Timur-Tamerlane, observed the movement of the Sun, describing it with unprecedented accuracy. The observatory with a radius of 40 m had the form of a sextant-trench with a south orientation and marble decoration.

The greatest astronomer of the European Middle Ages, who almost literally turned the world upside down, was Nicolaus Copernicus, who “moved” the Sun to the center of the universe instead of the Earth and proposed to consider the Earth as another planet.

And one of the most advanced observatories was Uraniborg, or Sky Castle, the property of Tycho Brahe, the Danish court astronomer. The observatory was equipped with the best, most accurate instrument at that time, had its own instrument-making workshops, a chemical laboratory, a storage of books and documents, and even a printing press for its own needs and a paper mill for paper production - royal luxury at that time!

In 1609, the first telescope appeared - the main instrument of any astronomical observatory. Its creator was Galileo. It was a reflecting telescope: the rays were refracted in it, passing through a series of glass lenses.

Kepler improved the telescope: in his device, the image was inverted, but of better quality. This feature eventually became standard for telescopic instruments.

In the 17th century, with the development of navigation, state observatories began to appear - the Royal Paris, the Royal Greenwich observatories in Poland, Denmark, Sweden. The revolutionary consequence of their construction and activities was the introduction of a time standard: it was now regulated by light signals, and then by telegraph and radio.

In 1839, the Pulkovo Observatory (St. Petersburg) was opened, which became one of the most famous in the world. Today there are more than 60 observatories in Russia. One of the largest on an international scale is the Pushchino Radio Astronomy Observatory, founded in 1956.

The Zvenigorod Observatory (12 km from Zvenigorod) has the only VAU camera in the world capable of carrying out mass observations of geostation satellites. In 2014, Moscow State University opened an observatory on Mount Shadzhatmaz (Karachay-Cherkessia), where they installed the largest modern telescope in Russia, with a diameter of 2.5 m.

The best modern foreign observatories

mauna kea- located on the Big Hawaiian Island, has the largest arsenal of high-precision equipment on Earth.

VLT complex("huge telescope") - located in Chile, in the Atacama "desert of telescopes".


Yerk Observatory in the United States, "the birthplace of astrophysics".

ORM Observatory(Canary Islands) - has an optical telescope with the largest aperture (ability to collect light).

Arecibo- located in Puerto Rico and owns a radio telescope (305 m) with one of the largest apertures in the world.

Tokyo University Observatory(Atacama) - the highest on Earth, located at the top of Mount Cerro Chainantor.