Astronomical instruments and devices - optical telescopes with various devices and radiation receivers, radio telescopes, laboratory measuring instruments and others technical means, used for conducting and processing astronomical observations.

The entire history of astronomy is connected with the creation of new instruments that make it possible to increase the accuracy of observations and the ability to study celestial bodies in the ranges of electromagnetic radiation (see. Electromagnetic radiation celestial bodies ), inaccessible to the naked human eye.

Goniometer instruments were the first to appear in ancient times. The oldest of them is the gnomon, a vertical rod that casts the sun's shadow on a horizontal plane. Knowing the length of the gnomon and shadow, you can determine the height of the Sun above the horizon.

Quadrants also belong to the ancient goniometric instruments. In its simplest form, a quadrant is a flat board in the shape of a quarter of a circle, divided into degrees. A movable ruler with two diopters rotates around its center.

Armillary spheres - models of the celestial sphere with its most important points and circles: the poles and axis of the world, meridian, horizon, celestial equator and the ecliptic. At the end of the 16th century. The best astronomical instruments in terms of accuracy and elegance were made by the Danish astronomer T. Brahe. His armillary spheres were adapted to measure both horizontal and equatorial coordinates of luminaries.

A radical revolution in the methods of astronomical observations occurred in 1609, when the Italian scientist G. Galileo used a telescope to view the sky and made the first telescopic observations. In improving the designs of refracting telescopes with lens objectives, great achievements belong to I. Kepler.

The first telescopes were still extremely imperfect; they produced a fuzzy image, colored with a rainbow halo.

They tried to get rid of the shortcomings by increasing the length of the telescopes. However, achromatic refracting telescopes, which began to be manufactured in 1758 by D. Dollond in England, turned out to be the most effective and convenient.

In 1668 I. Newton built a reflecting telescope, which was free from many of the optical disadvantages inherent in refractors. Later, M.V. was involved in improving this telescope system. Lomonosov and a V. Herschel. The latter achieved especially great success in the construction of reflectors. Gradually increasing the diameters of the manufactured mirrors, V. Herschel in 1789 polished the largest mirror (122 cm in diameter) for his telescope. At that time it was the greatest reflector in the world.

In the 20th century have become widespread mirror lens telescopes, the designs of which were developed by the German optician B. Schmidt (1931) and the Soviet optician D. D. Maksutov (1941).

In 1974, construction of the world's largest Soviet mirror telescope with a mirror diameter of 6 m was completed. This telescope was installed in the Caucasus - in Special Astrophysical Observatory. The possibilities of the new tool are enormous. Already the experience of the first observations showed that this telescope is accessible to objects of the 25th magnitude, i.e. millions of times weaker than those observed by Galileo through his telescope.

Modern astronomical instruments are used to measure the exact positions of luminaries on the celestial sphere ( systematic observations this kind allows us to study the movements of celestial bodies); to determine the speed of movement of celestial bodies along the line of sight ( radial velocities); to calculate geometric and physical characteristics celestial bodies; for studying physical processes, occurring in various celestial bodies; to determine them chemical composition and for many other studies of celestial objects that astronomy deals with.

Astrometric instruments include universal tool and a theodolite similar in design; meridian circle, used to compile accurate catalogs of star positions; passage instrument, serving for precise definitions moments of stars passing through the meridian of the observation site, which is necessary for time service.

Used for photographic observations astrographs.

For astrophysical research, telescopes with special devices designed for spectral ( objective prism, astrospectrograph), photometric ( astrophotometer), polarimetric and other observations.

It is possible to increase the penetrating power of a telescope by using television technology in observations ( see television telescope), and photomultiplier tubes.

Instruments have been created that allow observations of celestial bodies in various ranges of electromagnetic radiation, including in the invisible range. This radio telescopes and radio interferometers, as well as tools used in X-ray astronomy, gamma-ray astronomy, infrared astronomy.

For observations of some astronomical objects, special instrument designs have been developed. These are solar telescope, coronagraph (for observations solar corona), comet finder, meteor patrol, satellite photographic camera(for photographic observations of satellites) and many others.

During astronomical observations series of numbers, astrophotographs, spectrograms and other materials are obtained, which must be subjected to laboratory processing for final results. This processing is carried out using laboratory measuring instruments.

To measure the positions of star images on astrophotographs and images of artificial satellites relative to stars on satellitegrams, use coordinate measuring machines. To measure blackening in photographs of celestial bodies and spectrograms, use microphotometers.

An important instrument needed for observations is astronomical clock.

Electronic computers are used to process the results of astronomical observations.

Significantly enriched our understanding of the Universe radio astronomy, which originated in the early 30s. of our century. In 1943, Soviet scientists L.I. Mandelstam and N.D. Papaleksi theoretically substantiated the possibility of radar detection of the Moon. Radio waves sent by man reached the Moon and, reflected from it, returned to Earth. 50s XX century - the period is extraordinary rapid development radio astronomy. Every year, radio waves brought from space new amazing information about the nature of celestial bodies.

Today, radio astronomy uses the most sensitive receiving devices and the largest antennas. Radio telescopes have penetrated into depths of space that are still inaccessible to conventional optical telescopes. The radio cosmos opened up before man - a picture of the Universe in radio waves.

Astronomical observation instruments are installed on astronomical observatories. For the construction of observatories, places with a good astronomical climate are chosen, where the number of nights with clear skies is sufficiently large, and where atmospheric conditions are favorable for obtaining good images of celestial bodies in telescopes.

The Earth's atmosphere creates significant interference with astronomical observations. Constant movement air masses blur and spoil the image of celestial bodies, so in terrestrial conditions it is necessary to use telescopes with limited magnification (usually no more than several hundred times). Due to the absorption of ultraviolet and most wavelengths by the earth's atmosphere infrared radiation gets lost great amount information about objects that are sources of these radiations.

In the mountains, the air is cleaner, calmer, and therefore conditions for studying the Universe are more favorable there. For this reason, since late XIX V. all large astronomical observatories were built on mountain tops or high plateaus. In 1870, the French explorer P. Jansen used a balloon to observe the Sun. Such observations are carried out in our time. In 1946, a group of American scientists installed a spectrograph on a rocket and sent it into the upper atmosphere to an altitude of about 200 km. The next stage of transatmospheric observations was the creation of orbital astronomical observatories (OAO) at artificial satellites Earth. Such observatories, in particular, are Soviet orbital stations "Firework".

Orbital astronomical observatories of various types and purposes have become firmly established in practice modern research outer space.

ASTRONOMICAL INSTRUMENTS

Astronomical instruments have been used since ancient times. With the beginning of the development of agriculture, when it was necessary to plan agricultural work. To do this, it was necessary to determine the moments of the equinoxes and solstices. At the same time, the needs of nomadic livestock raising required the development of orientation methods. And for this purpose, stars and their movement were studied. Movement of the Sun and Moon. An example of an ancient observatory is the religious and astronomical building near Ryazan. Equinoxes and solstices were recorded by the shadow of the Sun and its coincidence with certain pillars.

Such structures were built everywhere where the first farmers of Aria settled. But they reached us in in the best possible way such ancient structures as the megaliths of Stonehenge.

Ancient astronomical observatory Jantar-Mantar.

In principle, the structure of these observatories is the same - the principle of sighting, that is, determining the direction from two points. However, these points were directed towards the horizon. That is, ancient observatories served the purpose of calendar counting days.

However, already among pastoralists, and especially with the development of navigation, there is a need to study the sky itself. Thus, already during the times of ancient eastern despotism (Sumer, Assyria, Babylon, Egypt), principles for systematizing celestial objects arose. The ideas of the ecliptic arise. It is divided into 12 parts. Constellations are formed and names are given to them. And observatories are being built. They practically did not reach us, but Ulugbek’s observatory was similar to them. In essence, this is an arc dug in the ground, on which the position of the stars was determined.

However, such a tool was useless to sailors. Therefore, hand-held astronomical instruments appear. It is known from history that in the second millennium BC. The Sea Peoples attacked Egypt. The peoples of the sea are the Pelasgians, Leleges, Etruscans and other peoples who belonged to the Indo-European Aryans. That is, our relatives and ancestors. They walked freely in the Mediterranean and Black Seas. And their ability to navigate, including by the Sun and stars, passed on to the Greeks.

This is how they appeared: Astronomical instruments or instruments: gnomon, armillary sphere, astrolabe, quadrant, octant, sextant, chronometer...

Antique astronomical instruments
and navigation tools

Armillary sphere	Astrolabe		Gnomon	Quadrant
Octant	Sextant	Marine chronometer	Nautical compass	Universal tool

Armillary spherethere is a collection of circles depicting the most important arcs celestial sphere. It aims to depict the relative position equator, ecliptic, horizon and other circles.

Astrolabe (from the Greek words: άστρον - luminary and λαμβάνω - I take), planisphere, analemma- a goniometric projectile used for astronomical and geodetic observations. A. was used by Hipparchus to determine the longitudes and latitudes of stars. It consists of a ring, which was installed in the plane of the ecliptic, and a ring perpendicular to it, on which the latitude of the observed star was measured after the diopters of the instrument were pointed at it. The difference in longitude between a given luminary and some other one was measured along a horizontal circle. In later times, A. was simplified; only one circle was left in it, with the help of which navigators measured the height of the stars above the horizon. This circle was suspended on a ring in a vertical plane, and by means of an alidade equipped with diopters, stars were observed, the height of which was measured on the limb, to which a vernier was subsequently attached. Later, spotting scopes began to be used instead of diopters, and, gradually improving, A. moved into new type instrument - theodolite, which is now used in all those cases where some measurement accuracy is required. In the art of surveying, A. continues to be used, where, with sufficiently careful calibration, it allows one to measure angles with an accuracy of minutes of arc.

Gnomon(ancient Greek γνώμων - pointer) - the oldest astronomical instrument, a vertical object (stele, column, pole), which allows one to determine the angular height of the sun by the shortest length of its shadow (at noon).

Quadrant(Latin quadrans, -antis, from quadrare - to make quadrangular) - an astronomical instrument for determining the zenithal distances of luminaries.

Octant(in maritime affairs - octane) - a goniometric astronomical instrument. The octant scale is 1/8 of a circle. The octant was used in nautical astronomy; almost out of use.

Sextant(sextant) - navigational measuring tool, used to measure the height of a luminary above the horizon for the purpose ofdefinitions geographical coordinates the area in which measurement is made.

The quadrant, octant and sextant differ only in the fraction of the circle (the fourth, eighth and sixth parts, respectively). Otherwise it is the same device. A modern sextant has an optical sight.

Astronomical Compendium is a set of small tools for mathematical calculations in a single case. It provided the user with many options in a ready-made format. This was not a cheap set and obviously indicated the wealth of the owner. This elaborate piece was made by James Kinvin for Robert Devereux, second Earl of Essex (1567 – 1601), whose arms, crest and motto are engraved on inside covers. The compendium includes a passage instrument for determining the time of night by the stars, a list of latitudes, magnetic compass, list of ports and harbours, perpetual calendar and lunar indicator. The compendium could be used to determine time, tide height in ports, as well as calendar calculations. We can say that this is an ancient minicomputer.

Optical instruments

A true revolution in astronomy began with Galileo's invention of the optical refracting telescope. The word “telescope” is formed from two Greek roots and can be translated into Russian as “I look into the distance.” Indeed, this optical device is a powerful telescope designed for observing very distant objects - celestial bodies. Created about four hundred years ago, the telescope is a unique symbol modern science, embodying humanity’s eternal desire for knowledge. Giant telescopes and grandiose observatories make a significant contribution to the development of entire fields of science devoted to the study of the structure and laws of our Universe. However, today a telescope can increasingly be found not in a scientific observatory, but in an ordinary city apartment, where an ordinary amateur astronomer lives, who on clear starry nights goes to experience the breathtaking beauty of space.

Although there is indirect evidence that optical devices intended for studying stars were already known to some ancient civilizations, the official date of birth of the telescope is considered to be 1609. It was in this year that Galileo Galilei, experimenting with lenses to create glasses, found a combination that provided multiple zooms. The first telescope built by the scientist became the ancestor of modern refractors and subsequently received the name telescope.

Galileo's telescope was a lead tube with two lenses: a plano-convex one, which served as an objective, and a plano-concave one, which served as an eyepiece. Galileo's first telescope provided a direct image and only three times magnification, but later the scientist managed to create a device that brought objects 30 times closer. Using his telescope, Galileo discovered the four satellites of Jupiter, the phases of Venus, irregularities (mountains, valleys, cracks, craters) on the surface of the Moon, and spots on the Sun. The Galilean telescope design was subsequently improved by Kepler, who created an instrument that offered an inverted image but had a significantly larger field of view and magnification. The lens telescope was further improved: to improve image quality, astronomers used the latest glass melting technologies, and also increased the focal length of telescopes, which naturally led to an increase in their physical dimensions (for example, late XVIII century, the length of Jan Hevelius's telescope reached 46 m).

The first reflecting telescope also appeared in the 17th century. This device was invented by Sir Isaac Newton, who, considering chromatism to be an insurmountable problem with refracting telescopes, decided to move in a different direction. In 1668, after much experimentation with alloys and mirror polishing technologies, Newton demonstrated the first reflecting telescope, which, with a length of only 15 cm and a mirror diameter of 25 mm, acted no worse than a long refracting telescope. Although the image created by Newton's first telescope was dim and not bright enough, the scientist subsequently managed to significantly improve the performance of his device.

In an effort to improve the design of the telescope in such a way as to achieve the highest possible image quality, scientists created several optical schemes using both lenses and mirrors. Among these telescopes greatest distribution received catadioptric systems of Newton, Maksutov-Cassegrain and Schmidt-Cassegrain, which will be discussed in more detail below.

Telescope design

A telescope is an optical system that, “snatching” a small area from space, visually brings objects located in it closer. The telescope captures rays of light parallel to its optical axis, collects them at one point (focus) and magnifies them using a lens or, more often, a system of lenses (eyepiece), which simultaneously converts the diverging rays of light into parallel ones.

Based on the type of element used to collect light rays at the focus, all modern consumer telescopes are divided into lens (refractor), mirror (reflector) and mirror-lens (catadioptric). The capabilities of telescopes of each group are somewhat different, therefore, in order to choose the optimal optical instrument for their needs, a novice amateur astronomer must have some understanding of its structure.

Lens telescopes (refractors)

Following their progenitor created by Galileo, telescopes of this group focus light using one or more lenses, as a result of which they are called lens or refractor.

Refractors have a number of advantages over telescopes of other systems. Thus, a closed telescope tube prevents dust and moisture from penetrating into the tube, which have a negative impact on the useful properties of the telescope. In addition, refractors are easy to maintain and operate - the position of their lenses is fixed at the factory, which eliminates the need for the user to independently make adjustments, that is, fine tuning. Finally, lens telescopes do not have central shielding, which reduces the amount of incoming light and leads to a distorted diffraction pattern. Refractors provide high contrast and excellent image resolution for observing planets. However, telescopes of this system also have disadvantages, the main of which is an effect known as chromatic aberration. It arises due to the fact that light rays of different lengths have unequal convergence, that is, the focal points for different components of the spectrum will be at different distances from the refractive lens. Visually, chromatic aberration appears as colored halos around bright objects. To eliminate this defect, additional lenses and optical elements made from special types of glass must be used. But the design of refractors itself requires at least two lenses, all four surfaces of which must have a well-calibrated curvature, be carefully polished and coated with at least one antireflective layer. In other words, a good refractor is a device that is quite complex to manufacture, and therefore, as a rule, very expensive.

Mirror telescopes (reflectors)

Telescopes other large group They collect a light beam using a mirror, which is why they are called mirror telescopes or reflectors. The most popular design of a reflecting telescope is called a Newtonian system telescope after its inventor.

The mirror, as an element of the optical system of the reflector, is a concave plate of parabolic glass, the front surface of which is covered with reflective material. When spherical mirrors are used in such designs, the light reflected by their surface does not converge at one point, forming a slightly blurry spot at the focus. As a result, the image loses contrast, creating an effect known as spherical aberration.

Parabolic mirrors help prevent image quality deterioration. In the left picture, the light reflected by spherical mirrors does not converge at one point, which leads to a deterioration in sharpness. In the right picture, paraboloid mirrors collect all the rays into a single focal point.

Light entering the telescope hits a mirror, which reflects the rays upward. Light is reflected to the focal point using
a flat secondary mirror of an elliptical shape, fixed in the center of the pipe at an angle of 45 degrees. Of course, the secondary mirror itself cannot be seen through the eyepiece, but it is an obstacle to the light flow and screens the light, which can change the diffraction pattern and lead to a slight loss of contrast. Among the advantages of reflectors is the absence of chromatism, because the rays of light, due to the design itself, are reflected from the glass and do not pass through it. In addition, compared to refractors, mirror telescopes are less expensive to manufacture: the reflector design contains only two surfaces that require polishing and special coatings.

Catadioptric telescopes - optical systems which combine lenses and mirrors. Catadioptric telescopes of the Newtonian system, Schmidt-Cassegrain and Maksutov-Cassegrain telescopes are presented here.

Mirror-lens telescopes of the Newtonian system differ from classical representatives of its class by the presence of a corrective lens on the path of the light flux to the focal point, which, while maintaining the compact dimensions of the telescope, allows for greater magnification. For example, when using a 2x magnification correction lens and a physical system length of 500 mm, the focal length will be 1000 mm. Such reflectors are much lighter and more compact than “normal” Newtonian telescopes of the same focal length, and, in addition, are easy to use
operation, easy to install and less susceptible to wind. The position of the corrective lens is fixed during production, but the mirrors, as in the case of a standard Newtonian telescope, require regular adjustment.

Optical circuits Schmidt-Cassegrain telescopes include thin aspherical correction plates that direct light onto a primary concave mirror to correct spherical aberration. After this, the light rays fall on the secondary mirror, which, in turn, reflects them down, directing them through the hole

at the center of the primary mirror. Directly behind the primary mirror is an eyepiece or diagonal mirror. Focusing is done by moving the primary mirror or eyepiece. The main advantage of telescopes of this design is the combination of portability and long focal length. The main disadvantage of Schmidt-Cassegrain telescopes is the relatively large secondary mirror, which reduces the amount of light and can cause some loss of contrast.

Telescopes of the Maksutov-Cassegrain system have a similar design. Just like Schmidt-Cassegrain systems, these models correct spherical aberration using a corrector, which, instead of a Schmidt plate, uses a thick convex-concave lens (meniscus). Passing through the concave side of the meniscus, light hits the primary mirror, which reflects it upward onto the secondary mirror (usually a mirror-coated area on the convex side of the meniscus). Then, just as in the Schmidt-Cassegrain design, the light rays pass through the hole in the primary mirror and enter the eyepiece. Maksutov-Cassegrain telescopes are less complex to manufacture than Schmidt-Cassegrain models, but the use of a thick meniscus in the optical design increases their weight.

Modern telescopes

Most modern telescopes are reflectors.

On this moment The world's largest reflecting telescopes are the two Keck telescopes located in Hawaii. Keck-I and Keck-II were commissioned in 1993 and 1996 respectively and have an effective mirror diameter of 9.8 m. The telescopes are located on the same platform and can be used together as an interferometer, giving a resolution corresponding to a mirror diameter of 85 m.

The world's largest telescope with a solid mirror is the Large Binocular Telescope, located on Mount Graham (USA, Arizona). The diameter of both mirrors is 8.4 meters.

On October 11, 2005, the Southern African Large Telescope in South Africa was launched into operation with a primary mirror measuring 11 x 9.8 meters, consisting of 91 identical hexagons.

Very big Telescope	Canary telescope	Telescope Hobby-Eberly	Gemini	SUBARU	SALT

Radio telescopes

Until the end of the Great Patriotic War Astronomical research was carried out only in the optical range using optical telescopes. However, already during the Second World War, radar stations began to be developed for the needs of detecting enemy aircraft. After the war, it was discovered that air defense radar stations were detecting some strange signals. It was discovered that these signals come from space. And so began the use of radio devices to explore the universe. Such devices were called radio telescopes. With their help, radio stars - quasars - were discovered, so they discovered cosmic microwave background radiation, radiation from the Sun, the center of the galaxy, etc. and so on. Radio telescopes have become a powerful tool for understanding the universe. And a great many of them were built.

At first these were small parabolic antennas:

Then more on towers with azimuth settings:

Then huge ones, with trusses turning on rails:

Sector ones, where part of the antenna paraboloid was mounted directly on the ground:

Radio telescopes began to be used together when the total power of individual telescopes was added up, giving the power and resolution of a larger telescope:

Arrays began to be created from individual telescopes,
which increased the resolution of the system:

In addition to parabolic antennas, lattice antennas began to be made:

Space radio telescopes:

The world's largest radio telescope

The Arecibo radio telescope is currently the largest in the world (using a single aperture). The telescope is used for research in the field of radio astronomy, atmospheric physics and radar observations of objects solar system. The Arecibo Astronomical Observatory is located in Puerto Rico, 15 km from Arecibo, at an altitude of 497 m above sea level. The research is being conducted by Cornell University in cooperation with the National Science Foundation.

Design Features: The telescope's reflector is located in a natural sinkhole and covered with 38,778 perforated aluminum plates (from 1 to 2 m), laid on a grid of steel cables. The antenna feed is movable, suspended on 18 cables to three towers. To conduct research under the radar astronomy program, the observatory has a 0.5 MW transmitter. Construction of the radio telescope began in 1960. The initial purpose of the telescope was to study the Earth's ionosphere. Author of the construction idea: Cornell University professor William Gordon. The official opening of the Arecibo Observatory took place on November 1, 1963.

Going beyond the optical range by radio astronomy immediately raised the question of using other ranges of electromagnetic radiation. In general, we can receive information about space in two ways - through electromagnetic radiation and corpuscular flows (flows elementary particles). There have been attempts to capture and gravitational waves, but so far without success.

Electromagnetic radiation is divided into:

radio waves,

infrared radiation,

light range,

ultraviolet radiation,

x-ray radiation,

gamma radiation.

Infrared (thermal) and ultraviolet radiation can be reflected by a regular mirror, so conventional reflector telescopes are used, but the image is perceived by special heat-sensitive sensors and ultraviolet radiation sensors.

X-ray and gamma radiation are a different matter. X-ray and gamma-ray telescopes are special instruments:

Astronomy and cosmonautics.

The main problem of observational astronomy is the earth's atmosphere. It is not completely transparent. It moves, including due to heat. Clouds and precipitation are frequent. There is a lot of dust in the atmosphere, insects, etc. Therefore, the dream of astronomers has always been the opportunity to place their instruments as high as possible. As high as possible into the mountains, onto airplanes and balloons. But the real revolution in this problem occurred with the launch Soviet Union artificial earth satellite. Almost immediately, astronomers and astrophysicists rushed to take advantage of the opportunity. First of all, by launching space probes to the Moon, Venus, Mars and on and on.

A brief description of the study of the Moon by Soviet scientists is presented on the page dedicated to the Moon.

Exploring the Solar System using automatic probes is a separate topic. Here we present the most famous astronomical instruments launched into orbit around the Earth.

Hubble	Herschel	Chandra	WISE	Spectr-R	Pomegranate

(source http://grigam.narod.ru)

Astronomical instruments and devices - optical telescopes with various devices and radiation receivers, radio telescopes, laboratory measuring instruments and other technical means used for conducting and processing astronomical observations.

The entire history of astronomy is associated with the creation of new instruments that make it possible to increase the accuracy of observations and the ability to conduct research on celestial bodies in the ranges of electromagnetic radiation (see) inaccessible to the naked human eye.

Goniometer instruments were the first to appear in ancient times. The oldest of them is the gnomon, a vertical rod that casts the sun's shadow on a horizontal plane. Knowing the length of the gnomon and shadow, you can determine the height of the Sun above the horizon.

Quadrants also belong to the ancient goniometric instruments. In its simplest form, a quadrant is a flat board in the shape of a quarter of a circle, divided into degrees. A movable ruler with two diopters rotates around its center.

Armillary spheres - models of the celestial sphere with its most important points and circles: the poles and axis of the world, the meridian, the horizon, the celestial equator and the ecliptic - were widely used in ancient astronomy. At the end of the 16th century. The best astronomical instruments in terms of accuracy and elegance were made by the Danish astronomer T. Brahe. His armillary spheres were adapted to measure both horizontal and equatorial coordinates of luminaries.

A radical revolution in the methods of astronomical observations occurred in 1609, when the Italian scientist G. Galileo used a telescope to view the sky and made the first telescopic observations. In improving the designs of refracting telescopes with lens objectives, great achievements belong to I. Kepler.

The first telescopes were still extremely imperfect; they produced a fuzzy image, colored with a rainbow halo.

They tried to get rid of the shortcomings by increasing the length of the telescopes. However, achromatic refracting telescopes, which began to be manufactured in 1758 by D. Dollond in England, turned out to be the most effective and convenient.

How to make an astrolabe?

You can make an astrolabe for measuring horizontal angles and determining the azimuths of luminaries with a compass and a protractor. The remaining necessary parts, in order not to distort the compass readings, must be made from available non-magnetic materials.

Cut a disk from multilayer plywood, PCB or plexiglass. The diameter of the disk should be such that it accommodates a circular scale (limbo) made from protractors and leaves behind it a free field 2-3 cm wide. If you have, for example, the smallest protractors produced with an arc with a diameter of 7.5 cm, then you will need a disk with a diameter of 14-15 cm.

Another important detail of the future astrolabe is the sighting bar. You can make it from a strip of brass or duralumin 2-3 cm wide and 5-6 cm longer than the diameter of the disk. Bend the ends of the strip protruding beyond the edge of the disk at a right angle upward and cut oblong or circular sight holes into them. On the horizontal part of the bar, symmetrically to the center, make two wider slots so that the dial readings can be seen through them. Attach the sight strip, ready for installation, in the middle using a bolt, washers and nuts to the center of the disk so that it can rotate in a horizontal plane. Attach the compass to the sight bar in the center. For this, as for installing the dial, use commercially available high-quality all-purpose adhesives. You can make a limb from two protractors (school protractors are made of light, non-magnetic material).

In 1668, I. Newton built a reflecting telescope, which was free from many of the optical disadvantages inherent in refractors. Later, M.V. Lomonosov and V. Herschel were involved in improving this system of telescopes. The latter achieved particularly great success in the construction of reflectors. Gradually increasing the diameters of the manufactured mirrors, V. Herschel in 1789 polished the largest mirror (122 cm in diameter) for his telescope. At that time it was the greatest reflector in the world.

In the 20th century Mirror-lens telescopes became widespread, the designs of which were developed by the German optician B. Schmidt (1931) and the Soviet optician D. D. Maksutov (1941).

In 1974, construction of the world's largest Soviet mirror telescope with a mirror diameter of 6 m was completed. This telescope was installed in the Caucasus - at the Special Astrophysical Observatory. The possibilities of the new tool are enormous. Already the experience of the first observations showed that this telescope could reach objects of the 25th magnitude, that is, millions of times fainter than those observed by Galileo in his telescope.

Modern astronomical instruments are used to measure the exact positions of luminaries on the celestial sphere (systematic observations of this kind make it possible to study the movements of celestial bodies); to determine the speed of movement of celestial bodies along the line of sight (radial velocities); to calculate the geometric and physical characteristics of celestial bodies; to study physical processes occurring in various celestial bodies; to determine their chemical composition and for many other studies of celestial objects that astronomy deals with.

Astrometric instruments include the universal instrument and the theodolite, which is similar in design; meridian circle, used to compile accurate catalogs of star positions; a passage instrument used to accurately determine the moments of the passage of stars through the meridian of the observation site, which is necessary for time service.

Astrographs are used for photographic observations.

For astrophysical research, telescopes with special devices are needed, designed for spectral (objective prism, astrospectrograph), photometric (astrophotometer), polarimetric and other observations.

It is possible to increase the penetrating power of a telescope by using television equipment in observations (see), as well as photomultipliers.

Instruments have been created that allow observations of celestial bodies in various ranges of electromagnetic radiation, including in the invisible range. These are radio telescopes and radio interferometers, as well as instruments used in X-ray astronomy, gamma-ray astronomy, and infrared astronomy.

For observations of some astronomical objects, special instrument designs have been developed. These include a solar telescope, a coronagraph (for observing the solar corona), a comet finder, a meteor patrol, a satellite photographic camera (for photographic observations of satellites) and many others.

During astronomical observations, series of numbers, astrophotographs, spectrograms and other materials are obtained, which must be subjected to laboratory processing for final results. This processing is carried out using laboratory measuring instruments.

Astronomical rake

This simple homemade instrument for measuring angles in the sky got its name from its resemblance to a garden rake.

Take two boards 60 and 30 cm long, 4 cm wide and 1-1.5 cm thick. Carefully treat their surface, for example, with fine abrasive sandpaper, and then fasten both boards together in the shape of the letter T.

Attach a sight - a small metal or plastic plate with a hole - to the free end of the longer board. Taking the target hole as the center of the circle, draw an arc with a radius of 57.3 cm on the plane of the smaller board using a cord of the appropriate size. Attach one end of it to the sight, and tie a pencil to the other end. Along the drawn arc, strengthen a row of teeth (pins) at a distance of 1 cm from each other. For pins, use pins or thin nails punched from the underside of the board (for safety, the nails should be dulled with a file). Two pins spaced 1 cm apart are visible at an angular distance of 1° when viewed through the sighting hole at a distance of 57.3 cm. In total, 21 or 26 pins need to be strengthened, which will correspond to the largest angle available for measurements, 20° or 25°. For ease of use of the tool, make the first, sixth, etc. teeth higher than the rest. Taller teeth will mark 5° intervals.

The size of the sighting hole must be such that all the pins can be seen through it at the same time.

To make your astronomical rake more enjoyable appearance, paint them with oil paint. Make the pins white - this way they will be better visible in the evening. Paint the smaller board with light and dark stripes, each 5 cm wide. Their boundaries should be high pins. This will also make it easier to work with the tool at night.

Before using an astronomical rake to observe celestial objects, test it to determine the angular sizes and distances between terrestrial objects during the daytime.

You will make more accurate angular measurements if you make the divisions 0.5°. To do this, either place the teeth at a distance of 0.5 cm from each other, or double the length of the larger plank. True, using an astronomical rake with a handle of such a long length is less convenient.

Coordinate measuring machines are used to measure the positions of images of stars on astrophotographs and images of artificial satellites relative to stars on satellitegrams. Microphotometers are used to measure blackening in photographs of celestial bodies and spectrograms.

An important instrument needed for observations is an astronomical clock.

Electronic computers are used to process the results of astronomical observations.

Radio astronomy, which emerged in the early 1930s, has significantly enriched our understanding of the Universe. of our century. In 1943, Soviet scientists L.I. Mandelstam and N.D. Papaleksi theoretically substantiated the possibility of radar detection of the Moon. Radio waves sent by man reached the Moon and, reflected from it, returned to Earth. 50s XX century - a period of unusually rapid development of radio astronomy. Every year, radio waves brought from space new amazing information about the nature of celestial bodies.

Today, radio astronomy uses the most sensitive receiving devices and the largest antennas. Radio telescopes have penetrated into depths of space that are still inaccessible to conventional optical telescopes. The radio cosmos opened up before man - a picture of the Universe in radio waves.

Astronomical observation instruments are installed at astronomical observatories. For the construction of observatories, places with a good astronomical climate are chosen, where the number of nights with clear skies is sufficiently large, and where atmospheric conditions are favorable for obtaining good images of celestial bodies in telescopes.

The Earth's atmosphere creates significant interference with astronomical observations. The constant movement of air masses blurs and spoils the image of celestial bodies, so in terrestrial conditions it is necessary to use telescopes with limited magnification (usually no more than several hundred times). Due to the absorption of ultraviolet and most of the wavelengths of infrared radiation by the earth's atmosphere, a huge amount of information about the objects that are the sources of these radiations is lost.

In the mountains, the air is cleaner, calmer, and therefore conditions for studying the Universe are more favorable there. For this reason, since the end of the 19th century. all large astronomical observatories were built on mountain tops or high plateaus. In 1870, the French explorer P. Jansen used a balloon to observe the Sun. Such observations are carried out in our time. In 1946, a group of American scientists installed a spectrograph on a rocket and sent it into the upper atmosphere to an altitude of about 200 km. The next stage of transatmospheric observations was the creation of orbital astronomical observatories (OAO) on artificial Earth satellites. Such observatories, in particular, are the Soviet Salyut orbital stations.

Orbital astronomical observatories of various types and purposes have become firmly established in the practice of modern space research.

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The entire history of astronomy is connected with the creation of ever new instruments that make it possible to increase the accuracy of observations and the ability to study celestial bodies in ranges inaccessible to the naked human eye.

In the history of astronomy, 4 main stages can be noted, characterized by different means of observation. At the 1st stage, dating back to ancient times, people, with the help special devices learned to determine time and measure angles between luminaries on the celestial sphere. Increasing the accuracy of readings was achieved mainly by increasing the size of instruments; the 2nd stage dates back to the beginning of the 17th century. and is associated with the invention of the telescope and, with its help, increasing the capabilities of the eye for astronomical observations. With the introduction of astronomical observations into practice spectral analysis and photographs in the mid-19th century. Stage 3 has begun. Astrographs and spectrographs made it possible to obtain information about chemical And physical properties celestial bodies and their nature. Development of radio engineering, electronics and astronautics in the mid-20th century. led to the emergence of radio astronomy and extra-atmospheric astronomy, which marked the 4th stage.

The first astronomical instrument can be considered a vertical pole fixed on a horizontal platform - a gnomon, which made it possible to determine the height of the Sun over many centuries. Knowing the length of the gnomon and the shadow, it is possible to determine not only the height of the Sun above the horizon, but also the direction of the meridian, establish the days of the onset of spring and autumn equinox and winter and summer solstices.

The development of designs for astronomical instruments in China since ancient times apparently proceeded independently of similar work on Bl. and Wed. East and West. So, in the 7th century. BC. in China, in the kingdom of Lu, the gnomon was already used. In ancient Greece, a few decades later, the gnomon was used by Anaximander (610-540 BC). The ancient Chinese gnomon was a vertically mounted pole about 1.5-2 m high with an elongated rectangular platform at the base, on which the divisions necessary for measurements were marked. By the length of the midday shadow on this site, the moments of the solstices and equinoxes were determined

Ancient Chinese gnomon

Reliable information about ancient Greek astronomical instruments became the property of subsequent generations thanks to "Almagest" in which, along with the methodology and results of astronomical observations, C. Ptolemy provides a description of astronomical instruments - the gnomon, the armillary sphere, the astrolabe, the quadrant, the parallax ruler - used both by his predecessors (especially Hipparchus) and those created by him. Many of these tools were further improved and used for many centuries.

Quadrants also belong to the ancient goniometric instruments. In its simplest form, a quadrant is a flat board in the shape of a quarter of a circle, divided into degrees. A movable ruler with two diopters rotates near the center of this circle.

Armillary spheres - models of the celestial sphere with its most important points and circles: the poles and axis of the world, the meridian, the horizon, the celestial equator and the ecliptic - were widely used in ancient astronomy. At the end of the 16th century. The best astronomical instruments in terms of accuracy and elegance were made by the Danish astronomer T. Brahe. His armillary spheres were adapted to measure both horizontal and equatorial coordinates of luminaries. The earliest known most complete armillary sphere is one created in Alexandria in 140 AD. meteoroscope with nine rings. However, simpler types of armillary spheres existed in the West before. Ptolemy speaks of three such instruments. It has been established that in 146-127. BC. an armillary sphere of four rings was used by Hipparchus.

An instrument that represents a further step in the development of astronomical instruments compared to the armillary sphere is the torquetum, invented by the Arabs. In this device, the rings are not nested inside each other, but are mounted on separate stands, which is more convenient and perfect than in an armillary sphere, in which all the rings are concentric.

The famous “Simplified Instrument” is the Torquetum of Gou Shoujing, made in 1270 and currently located at the Purple Mountain Observatory in Nanjing (China).

J. Needham pointed out that the "Simplified Device" - jianyi Guo Shoujing is the harbinger of all equatorial installations of modern telescopes. In his opinion, knowledge of the structure of this device three centuries later came to the Danish astronomer Tycho Brahe and led him to equatorial astronomy and the design of corresponding instruments. As for the very transfer of the idea of ​​​​the equatorial torquetum from China, J. Needham believes that it occurred through the Arabs to the famous Flemish mathematician, doctor and astronomer Gemma Frisius in 1534, and from him to Tycho Brahe. And through the latter and his successor, Johannes Kepler, modern European astronomy came to become equatorial in the Chinese manner. It should be noted, however, that since the time of Guo Shoujing, no further significant advances have been made in the designs of our modern equatorial installations.

During the early Middle Ages, the achievements of ancient Greek astronomers were accepted by scientists of the Near and Middle East and Central Asia, who improved their instruments and developed a number of original designs. There are known works on the use of astrolabes and their designs, on sundials and gnomons, written by al-Khorezmi, al-Fergani, al-Khojendi, al-Biruni and others. A significant contribution to the development of astronomical instruments was made by astronomers of the Maragha Observatory (Nasireddin Tuey, 13 c) and the Samarkand Observatory (Ulugbek, 15 c), on which a giant sextant with a radius of about 40 was installed m.

Through Spain and Southern Italy, the achievements of these astronomers became known in Northern Italy, Germany, and England France. In the 15-16th centuries. European astronomers used, along with instruments of their own design, those described by Eastern scientists. The instruments of G. Purbach, Regiomontanus (I. Müller), and especially Tycho Brahe and J. Hevelius, who created many original instruments of high precision, became widely known.

Heavenly bodies have interested people since time immemorial. Even before the revolutionary discoveries of Galileo and Copernicus, astronomers made repeated attempts to find out the patterns and laws of motion of planets and stars and used special instruments for this.

The tools of ancient astronomers were so complex that it took modern scientists years to understand their structure.

1. Warren Field Calendar

Although the strange depressions at Warren Field were discovered from the air in 1976, it was not until 2004 that it was determined to be ancient. moon calendar. Scientists believe that the found calendar is about 10,000 years old.

It looks like 12 depressions located in an arc of 54 meters. Each hole is synchronized with lunar month in the calendar, and adjusted for the lunar phase.

Also surprising is that the calendar at Warren Field, which was built 6,000 years before Stonehenge, is oriented to the point of sunrise on the winter solstice.

2. Al-Khujandi sextant in painting

Very little information has survived about Abu Mahmud Hamid ibn al-Khidr Al-Khujandi, other than that he was a mathematician and astronomer who lived in what is now Afghanistan, Turkmenistan and Uzbekistan. He is also known to have created one of the largest astronomical instruments in the 9th and 10th centuries.

His sextant was made in the form of a fresco, located on a 60-degree arc between the two interior walls of the building. This huge 43-meter arc was divided into degrees. Moreover, each degree was divided into 360 parts with jewelry precision, which made the fresco a stunningly accurate solar calendar.

Above the Al-Khujandi arc there was a domed ceiling with a hole in the middle, through which the sun's rays fell on the ancient sextant.

3. Volvelles and the Zodiac Man

In Europe at the turn of the 14th century, scientists and doctors used a rather strange type of astronomical instrument - the volvelle. They looked like several round sheets parchment with a hole in the center, superimposed on each other.

This made it possible to move the circles to calculate all the necessary data - from the phases of the Moon to the position of the Sun in the Zodiac. In addition to its main function, the archaic gadget was also a symbol of status - only the richest people could acquire a Volvella.

Also, medieval doctors believed that every part human body ruled by its constellation. For example, Aries was responsible for the head, and Scorpio was responsible for the genitals. Therefore, for diagnosis, doctors used volvelles to calculate the current position of the Moon and the Sun.

Unfortunately, volvelles were quite fragile, so very few of these ancient astronomical instruments survive.

4. Ancient sundial

Today, sundials are used only to decorate garden lawns. But they were once necessary to track time and the movement of the Sun across the sky. One of the oldest sundials was found in the Valley of the Kings in Egypt.

They date back to 1550 - 1070 BC. and are a round piece of limestone with a semicircle drawn on it (divided into 12 sectors) and a hole in the middle into which a rod was inserted to cast a shadow.

Soon after the discovery of the Egyptian sundial, similar ones were found in Ukraine. They were buried with a person who died 3200 - 3300 years ago. Thanks to the Ukrainian clock, scientists learned that the Zrubna civilization had knowledge of geometry and was able to calculate latitude and longitude.

5. Heavenly disk from Nebra

Named after the German city where it was discovered in 1999, the Nebra Sky Disk is the oldest image of the cosmos ever discovered by man. The disk was buried next to a chisel, two axes, two swords, and two chainmail bracers about 3,600 years ago.

The bronze disk, covered with a layer of patina, had gold inserts depicting the Sun, Moon and stars from the constellations Orion, Andromeda and Cassiopeia. No one knows who made the disk, but the alignment of the stars suggests that the creators were located at the same latitude as Nebra.

6. Chanquillo Astronomical Complex

The ancient astronomical observatory of Chanquillo in Peru is so complex that its true purpose was only discovered in 2007 by computer program, designed for aligning solar panels.

The 13 towers of the complex are built in a straight line 300 meters long along the hill. Initially, scientists thought that Chanquillo was fortifications, but for the fort it was incredible bad place, since it had no defensive advantages, no running water, no sources of food.

But then archaeologists realized that one of the towers looked at the sunrise point at the summer solstice, and the other looked at the sunrise point at winter solstice. Built about 2,300 years ago, the towers are the oldest solar observatory in America. Using this ancient calendar, it is still possible to determine the day of the year with a maximum two-day error.

Unfortunately, the huge solar calendar from Chanquillo is the only trace of the civilization of the builders of this complex, who preceded the Incas by more than 1,000 years.

7. Star atlas of Hygina

The Hyginus Star Atlas, also known as the Poetica Astronomica, was one of the first works to depict the constellations. Although the atlas's authorship is disputed, it is sometimes attributed to Gaius Julius Hyginus (Roman writer, 64 BC - 17 AD). Others claim that the work bears similarities to the works of Ptolemy.

In any case, when the Poetica Astronomica was reprinted in 1482, it became the first printed work to show the constellations, as well as the myths associated with them.

While other atlases provided more specific mathematical information that could be used for navigation, the Poetica Astronomica provided a more whimsical, literary interpretation of the stars and their history.

8. Celestial globe

The celestial globe appeared back when astronomers believed that stars moved across the sky around the Earth. Celestial globes, which were created to display this celestial sphere, began to be created by the ancient Greeks, and the first globe in a form similar to modern globes was created by the German scientist Johannes Schöner.

At the moment, only two Schöner celestial globes have survived, which are true works of art depicting constellations in the night sky. The oldest surviving example of a celestial globe dates back to around 370 BC.

9. Armillary sphere.

An armillary sphere is an astronomical instrument in which several rings surround center point- was a distant relative of the celestial globe.

There were two different types spheres - observational and demonstration. The first scientist to use such spheres was Ptolemy.

Using this instrument, it was possible to determine the equatorial or ecliptic coordinates of celestial bodies. Along with the astrolabe, the armillary sphere has been used by sailors for navigation for many centuries.

10. El Caracol, Chichen Itza

The El Caracol Observatory at Chichen Itza was built between 415 and 455 AD. The observatory was very unusual - while most astronomical instruments were set up to observe the movement of the stars or the Sun, El Caracol (translated as "snail") was built to observe the movement of Venus.

For the Mayans, Venus was sacred - literally everything in their religion was based on the cult of this planet. El Caracol, in addition to being an observatory, was also a temple to the god Quetzalcoatl.