Description of telescopes purpose. What is a telescope? Types, characteristics and purpose of telescopes. The largest optical telescopes

The sky beckons us when we look at its open spaces. What is hidden behind the clouds, and what is in its impenetrable darkness? Of course, we were able to get some idea of ​​these questions with the help of a telescope. Undoubtedly, this is a unique device that gave us a magnificent picture of space. And undoubtedly, it brought our understanding of the heavenly space closer.

It is known that the first telescope was created by Galileo Galilei. Although few people know that he used the early discoveries of other scientists. For example, the invention of the telescope for navigation.
In addition, glass craftsmen have already created glasses. In addition, lenses were used. And the effect of refraction and magnification of glass has been more or less studied.

Galileo's first telescope

Of course, Galileo achieved a significant result in the study of this area. In addition, he collected and improved all the developments. And as a result, he developed and introduced the world's first telescope. In truth, it only had a threefold increase. But it was distinguished by high image quality at that time.

By the way, it was Galileo who called his developed object a telescope.
In the future, the scientist did not stop there. He improved the device up to twenty times the image magnification.
It is important that Galileo not only developed the telescope. Moreover, he was the first to use it for space exploration. In addition, he made a lot of astronomical discoveries.

Telescope characteristics

The telescope consists of a tube that stands on a special mount. It is equipped with axes for aiming at the observed object.
In addition, the optical device has an eyepiece and a lens. Moreover, the rear plane of the lens is perpendicular to the optical axis, and is connected to the front surface of the eyepiece. Which, by the way, is similar to the objective in relation to the optical axis.

It is worth noting that a special device is used for focusing.
The main characteristics of telescopes are magnification and resolution.
Image magnification depends on the focal length of the eyepiece and the object.
Resolution is related to the refraction of light. Thus, the size of the observed object is limited by the resolution of the telescope.

Types of telescopes in astronomy

The varieties of telescopes are associated with different construction methods. More precisely, the use of various tools as a lens. In addition, it matters for what purpose the device is needed.
Today, there are several main types of telescopes in astronomy. Depending on the light-harvesting component, they are lens, mirror and combined.

Lens telescopes (diopter)

In other words, they are called refractors. These are the very first telescopes. In them, light is collected by a lens, which is bounded by a sphere on both sides. Therefore, it is considered biconvex. In addition, the lens is a lens.
Interestingly, you can use not just a lens, but a whole system of them.

It is worth noting that convex lenses refract light rays and bring them into focus. And in it, in turn, an image is built. An eyepiece is used to view it.
What is important, the lens is set so that the focus and the eyepiece coincide.
By the way, Galileo invented the refractor. But modern devices consist of two lenses. One of them collects light, and the other scatters. That allows to reduce deviations and errors.

Mirror telescopes (cataptric)

They are also called reflectors. Unlike the lens type, their lens is a concave mirror. It collects starlight at one point and reflects it to the eyepiece. In this case, the errors are minimal, and the decomposition of light into rays is completely absent. But the use of a reflector limits the field of view of the observer.
Interestingly, mirror telescopes are the most common in the world. Because their development is much easier than, for example, lens devices.

Catadioptric telescopes (combined)

These are mirror lenses. They use both lenses and mirrors to produce images.

In turn, they were divided into two subspecies:
1) Schmidt-Cassegrain telescopes - they have a diaphragm installed in the very center of the curvature of the mirror. This eliminates spherical disturbances and deviations. But the field of view and image quality increase.
2) Maksutov-Cassegrain telescopes - a plano-convex lens is installed in the region of the focal plane. As a result, field curvature and spherical deflection are prevented.

It should be noted that in modern astronomy, it is the combined type of instruments that is most often used. By mixing two different elements to collect light, they produce better data.

Such devices are capable of receiving only one wave of signals. Antennas transmit signals and process them into images.
Radio telescopes are used by astronomers for scientific research.

Infrared telescope models

They are very similar in design to optical mirror telescopes. The principle of obtaining an image is almost the same. The rays are reflected by the lens and are collected at one point. Next, a special device measures the heat and photographs the result.

Modern telescopes

A telescope is an optical instrument for observation. It was invented almost half a century ago. During this time, scientists changed and improved the device. Indeed, many new models have been created. Unlike the first ones, they have an increased quality and an increase in the image.

In our age of technology, computer telescopes are used. Accordingly, they are equipped with special programs. What is important, the modern prototype takes into account that each person's perception of the eyes is different. For high accuracy, the image is transmitted to the monitor. Thus, the image is perceived as it really is. In addition, this way observation eliminates any distortion.

In addition, scientists of our generation use not one device at the same time, but several. Moreover, unique cameras are connected to the telescope, which transmit information to a computer. This allows you to get clear and accurate information. Which, of course, are used to study and.

Interestingly, now telescopes are not just instruments for observation. But also devices for measuring distances between space objects. For this function, spectrographs are connected to them. And the interaction of these devices provides specific data.

Other classification

There are also other types of telescopes. But they are used for their own purpose. For example, X-ray and gamma-ray telescopes. Or ultraviolet devices that filter the picture without processing and exposure.
In addition, devices can be divided into professional and amateur. The former are used by scientists and astronomers. Obviously, the latter are suitable for home use.

How to choose a telescope for astronomy lovers

Choosing a telescope for astronomy enthusiasts is based on what you want to observe. In principle, the types and characteristics of devices are described above. You just need to choose which one you like best. It is better, in my opinion, to dwell on a lens or a combined form. But the choice, of course, is yours.

According to the Internet, the best amateur telescopes are represented by companies: Celestron, Bresser and Veber.

The telescope has been studying the life of planets for hundreds of years

The creation and development of the telescope, in fact, made it possible to make a huge step in space exploration. Probably everything we know was formed with the help of this device. Although, of course, one should not underestimate the very activities of scientists.
Today we looked at some types of telescopes and their characteristics. Definitely, the progress of technology is visible. And as a result, we learned a lot of interesting things about space objects and space itself. In addition, we can admire the beautiful sky and get to know it thanks to this wonderful invention.

Telescopes do not occupy the widest niche on the Russian market of optical equipment, but the assortment here is quite decent and is represented by products from many well-known companies.

Large manufacturers offer optics for users of different levels. There are already full-fledged series for beginners and even inexpensive devices specially designed for children and adolescents.

Telescopes for professionals are still a matter of special pride for eminent brands - not just optical devices, but high-tech and “smart” devices.

The best sellers in 2017 were amateur and semi-professional telescopes from the following manufacturers:

• sky-watcher;
• Celestron;
• Bresser;
• Veber.

The principle of operation and the device of the telescope

A telescope is a complex optical device with which you can see distant objects (astronomical or terrestrial) in multiple magnification.

Structurally, it is a tube, at one end of which there is a light-collecting lens and / or a concave mirror - an objective. On the other is the eyepiece - through it we just examine the resulting image.

add from my telescope with inscriptions

Also the design of the telescope includes:

1. Finder to detect specific astronomical objects;

2. Light filters that muffle too bright stars;

3. Diagonal mirrors (corrective plates) that turn the image that the lens transmits “upside down”.

Professional models with astrophotography and video capabilities can be additionally equipped with the following elements:

1. Sophisticated electronic equipment;

2. GPS system;

3. Electric motor.

Types of telescopes

Refractors (lensed)

You can recognize such a telescope by its simple design, similar to a spyglass. The lens and the eyepiece are on the same axis here, and the enlarged image is transmitted in a straight line - as in the very first devices invented 400 years ago.

Refractors, or refracting telescopes, collect the reflected light of celestial bodies with the help of 2-5 biconvex lenses spaced at both ends of a long body tube. This type of device is more suitable for beginners and lovers of astroobservations, as it allows you to have a good look at terrestrial objects and celestial bodies within our solar system.

Lenses installed in refractors decompose the light "caught" by the lens into spectral components, which leads to some loss of image clarity and makes it dimmer at too high magnification. It is recommended to use such a telescope in an open area outside the city, where the illumination of the sky is minimal.

• Easy to operate and do not require specialized maintenance;
• The tight design is protected from hit of dust and moisture;
• Not afraid of temperature changes;
• They give out a clear and contrasting picture of nearby astronomical bodies;
• They have a long service life.

• Quite bulky and heavy (the weight of some models reaches 25 kg);
• The maximum lens diameter is 150 mm;
• Not suitable for observations in the city.

Depending on the type of lenses installed, telescopes are divided into the following types:

1. Achromatic - have small and medium degrees of magnification, but give a flat picture.

2. Apochromatic - make the image more convex, but eliminate defects such as a blurry contour and the manifestation of a secondary spectrum.

Reflectors (mirror)

The reflector captures and transmits the light beam using two concave mirrors: one is in the tube lens, the other reflects the image at an angle, sending it to the side eyepiece.

Unlike a refractor, such optics are more suitable for studying deep space and obtaining high-quality images of distant galaxies. The production of mirrors is cheaper than lenses, which is reflected in the cost of devices. However, it will be difficult for a beginner or child to cope with complex settings and image correctors.

• Simplicity of design;
• Compact size and light weight;
• They perfectly capture the dim light of distant cosmic bodies;
• Large aperture (from 250 to 400 mm), giving a brighter and clearer image without defects;
• More low price compared to similar refractors.

• Requires time and experience to set up;
• Dust or dirt may enter the open structure of the device;
• Afraid of temperature changes;
• Not suitable for observing terrestrial and nearby objects in the solar system.

Catadioptrics (mirror-lens)

The lens of catadioptric telescopes is assembled from lenses and mirrors, so it combines their advantages and maximally compensates for defects with the help of special correction plates.

The image of both distant and near astronomical objects in such a device approaches the ideal, which allows not only to observe the stars, but also to take high-quality pictures.

• Compact dimensions and portability;
• Equally well suited for observations of objects in deep and near space;
• Give the highest quality image;
• Aperture up to 400 mm.

• High price;
• Long time of thermal stabilization of the air inside the pipe;
• Complicated design.

Telescope selection options

Having decided to buy a telescope, you should decide on your basic requirements for this device.

The design and characteristics of the optics will depend on your answers to a number of questions:

1. What kind of objects would you like to consider - planets within our solar system or distant galaxies?

2. From where will you observe cosmic bodies - from your balcony do you have the opportunity to travel with a telescope to the field?

3. Do you plan to do astrophotography?

Now let's move on to the main characteristics of modern telescopes.

Parabolic or spherical mirror

The design of a spherical mirror is such that it cannot reflect all the rays to one point. Because of this, ideally sharp focus is unattainable for reflectors with spherical optics. This phenomenon is called "spherical aberration" and is most pronounced at high magnifications.

A parabolic mirror is not subject to spherical aberrations and is able to collect light rays into one point. At high magnification, you will not have any problems with focusing, and the distant object will be visible clearly and in all details.

But not everything is so bad with spherical mirrors. With a certain ratio between the mirror diameter and the focal length, such a mirror works almost like a parabolic one. A telescope with a mirror with a diameter of 114 mm and a focal length of 900 mm is practically devoid of spherical aberrations and focuses the image well up to the value of the maximum useful magnification.

Aperture (lens diameter)

The main criterion for choosing a telescope is the aperture of its objective. It determines the ability of a lens or mirror to collect light: the higher this characteristic, the more reflected rays will enter the lens. This means that it will give high image quality and will even be able to capture the weak reflected radiation of distant space objects.

When choosing an aperture for your purposes, be guided by the following numbers:

1. To obtain a clear picture of nearby planets or satellites, a device with a lens diameter of up to 150 mm is enough. In urban conditions, it is better to reduce this figure to 70-90 mm.

2. A device with an aperture of more than 200 mm will be able to see distant galaxies.

3. If you are planning to indulge in your favorite hobby in areas far from the city with a low-light night sky, you can try the maximum size of semi-professional lenses - up to 400 mm.

Focal length

The focal length is the distance from the lens to the point in the eyepiece where all the light rays are again collected in a beam. The degree of magnification and the quality of the visible image depend on this indicator - the higher it is, the better we will consider the object of interest.

Focus increases the length of the telescope itself, which is reflected in the convenience of its storage and transportation. Of course, on the balcony it is more convenient to keep a short-focus device, where F does not exceed 500-800 mm. This limitation does not apply only to catadioptrics - in them the light flux is refracted many times, and does not go in a straight line, which makes it possible to significantly shorten the body.

Magnification

The magnification of objects can be corrected by putting a more powerful or weaker eyepiece - today manufacturers offer optics with F from 4 to 40 mm, as well as Barlow lenses that double the focus of the telescope itself.

1. In detail, it makes sense to consider only close space bodies (the Moon, for example).

2. For observing distant galaxies, a high magnification factor is not so important.

Mount Type

Mounting (stand for the telescope) is necessary in order to make the device convenient to use.

Complete with amateur and semi-professional optics usually comes one of 3 main types of special movable supports:

1. Azimuthal - the simplest stand that allows you to move the telescope horizontally and vertically. Most often, it is equipped with refractors and small catadioptrics. But for astrophotography, an azimuthal mount is not suitable, because it does not allow you to capture a clear picture.

2. Equatorial - has an impressive weight and dimensions, but it helps to find the necessary object at the given coordinates. Such a tripod is ideal for reflectors who "see" distant galaxies that are indistinguishable to the naked eye. The equatorial is also popular among fans of astrophotography.

3. The Dobson system is a compromise between an easy-to-use and cheap azimuth base and a reliable equatorial design. Often comes with powerful and expensive reflectors.

Optical design

Telescope of Galileo (1609)

A simple telescope design, similar to that used by Galileo in the first astronomical two-lens telescopes. A long-focus converging (convex) lens plays the role of an objective, and the other (concave) lens plays the role of an eyepiece; the result is a straight image. Such a system is still used in theatrical binoculars.

Kepler telescope (1611)

A simple telescope system that uses convex lenses as both objective and eyepiece. This gives a larger field of view and higher magnification than can be obtained with a Galilean telescope, but the image in a Keplerian telescope is upside down.

Telescope of the Gregory system (1663)

A type of reflecting telescope proposed by James Gregory in 1663. The primary mirror is a paraboloid with a central hole, and the secondary is an ellipsoid. Gregory was unable to obtain mirrors of the desired configuration, so he could not build his telescope before Newton created his first reflector of a simpler design with a flat secondary mirror. Subsequently, the Gregory system was superseded by the Cassegrain telescope

Newton's telescope (1668)

A simple type of reflecting telescope designed by Isaac Newton (1642-1727) who demonstrated it at the Royal Society of London in 1671. The telescope's primary mirror is a paraboloid (a spherical mirror can be used for small apertures) and the secondary mirror is a flat mirror placed on path of the reflected beam at an angle of 45° to the optical axis, so that the image is formed outside the main tube. The design is widely used for small amateur instruments, but not suitable for large telescopes.

Diagram of Cassegrain (1672)

A reflecting telescope in which the focus of the image is directly behind the central hole in the primary mirror. This design was proposed by Jacques Cassegrain (1652-1712), professor of physics in the city of Chartres in France around 1672, i.e. four years after Issac Newton created the first reflector. In this telescope, the secondary mirror is convex, not flat (as in the Newtonian design). Cassegrain himself did not build the telescope, so several years passed before his idea was realized. Today, the Cassegrain focus is popular and widely used in both modest amateur instruments and large professional telescopes.

Herschel telescope (1772)

A type of reflecting telescope designed by William Herschel (1738-1822) in which the parabolic primary mirror is tilted so that the focus lies outside the telescope's main tube and can be accessed without blocking the incoming light. This idea was put into practice by Lomonosov 10 years earlier. The disadvantage of the system is the presence of distortions, which is why this type of telescope was subsequently replaced by other reflector systems.

Ritchey-Chrétien telescope (1922)

A telescope whose optical system is similar to that of a Cassegrain telescope, except that both the primary and secondary mirrors are hyperboloid-shaped. As a result, the Ritchey-Chrétien telescope provides a wide field of view in the absence of coma.

Serurier system (1930)

The open tube design of a large reflecting telescope, ensuring that deflection is uniform as the telescope's orientation changes. It is impossible to make the tube of the largest telescopes completely indeformable. The design of the 200-inch tube of the Hale Telescope proposed by Mark Serurier does not eliminate the deformation, but maintains the optical axis of the telescope

Schmidt Camera (1930)

A type of astronomical telescope with a wide field of view intended solely for photographic use. It was invented by Bernard Schmidt in 1930. A spherical mirror acts as a light collector. Correction of spherical aberration is carried out using a thin glass plate of a complex profile, installed at the input end of the telescopic tube (behind the focus). The photographic plate is placed at the primary focus. Since the focal surface is curved, the photographic plate is given the same shape using a special holder. The result is sharp, undistorted images of a very wide field of view - up to tens of degrees across.

Dell-Kirkham Telescope

A variation of the Cassegrain telescope in which the primary mirror has an ellipsoid profile rather than the more conventional paraboloid. The secondary mirror is spherical. As a result, the field of view is much smaller than that of a standard Cassegrain telescope of the same size.

Maksutov telescope (1940)

A reflecting telescope in which the optical distortions of a spherical primary mirror are corrected by a concave lens (meniscus), which provides a high-quality image over a wide field of view. The telescope was invented by D.D. Maksutov (1896-1964).

The main structure of the telescope is a typical Cassegrain system. A small secondary mirror is mounted behind the corrective lens, and the image is formed directly behind the primary mirror, which has a small central hole.

The difficulty of creating large corrective lenses limits the professional use of such a telescope, but Maksutov telescopes, which have a compact tube and a wide field of view at a low focal ratio, are popular with amateur astronomers.

Depending on the direction of the output beam, there are modifications of this system: Maksutov-Cassegrain and Maksutov-Newton.

Schmidt-Cassegrain telescope (1940, 1942)

An optical telescope design that combines the features of a Schmidt camera and a Cassegrain reflector. Suggested by D.D. Baker (1940) and C.R. Birch (1942).

This telescope uses a spherical primary mirror and a correction plate to compensate for spherical aberration, similar to the Schmidt camera. However, the photographic plate holder at the primary focus is replaced by a small, convex secondary mirror that reflects light back into the tube through a hole in the primary mirror. As a result, one can either view the image visually or install a camera in the main tube behind the primary mirror.

A telescope of this design turns out to be very compact, which is especially important for portable telescopes and telescopes for amateur and general educational purposes.

Paul-Baker system (1935, 1945)

The optical design of a reflecting telescope that has an exceptionally wide field of view with good resolution. It uses a parabolic primary mirror with a focal ratio of f/4 or less, a convex spherical secondary mirror, and a concave spherical third mirror whose curvature is equal to but opposite in sign to that of the secondary. The design was proposed by the French optician Maurice Paul in 1935 and independently by James Baker around 1945.

Baker-Nunn Camera (1957)

A variation of the Schmidt camera designed for photographing artificial earth satellites.

Baker-Schmidt system

Modification of the Schmidt camera, which uses the technical means proposed by J. G. Baker to eliminate aberration and distortion.

Willstrop telescope

Design of reflective optical telescopes that provide good images in a field of view of 5° or more. The design is a modified version of the Paul-Baker system. The hole in the primary mirror has a diameter that is 60% of the diameter of the entire mirror, and the focus lies in this hole. The shape of all three mirrors differs significantly from parabolic or spherical. The advantage of Willstrop's design is that the telescope is much more compact than the Schmidt camera. In addition, it does not produce virtual images caused by internal reflections, as in the corrective lens of a Schmidt camera. This design makes it possible to build a telescope that would be more powerful than any of the existing Schmidt cameras.

Dobson telescope (1960s-1970s)

Inexpensive large-aperture reflecting telescope with a simple unguided altazimuth setup. Its design is convenient for amateur astronomers, and its portability is especially important. The telescope bears the name of the author of the concept and the first developments carried out in the 1960s-1970s, John Dobson of the San Francisco Society of Amateur Astronomers. The glued wooden tube of the telescope is mounted in a box, which is mounted on a base plate and can rotate around a vertical axis. A semi-circular bracket with stops at the top of the box has trunnions attached to opposite sides of the pipe. To ensure that the movement around both axes is even, Teflon is used. Dobson was also able to show that sheet glass (which is thinner than mirror glass commonly used) can be made into an inexpensive large mirror of good quality. To avoid distortion, a thin mirror should rest freely on a carpet or rubber pad.

Telescopes of Galileo

In 1609, having learned about the invention of the telescope by Dutch opticians, Galileo independently made a telescope with a plano-convex lens and a plano-concave eyepiece, which gave a threefold increase. After some time, he made telescopes with 8- and 30-fold magnification.

In 1609, starting observations with a telescope, Galileo discovered dark spots on the moon, which he called the seas, mountains and mountain ranges. January 7, 1610 discovered four satellites of the planet Jupiter, found that the Milky Way is a cluster of stars. These discoveries are described by him in the essay “The Starry Messenger, Revealing Great and Most Amazing Spectacles…” (published on March 12, 1610).

Resolving power (resolution) of the telescope

This parameter characterizes the ability telescope to distinguish fine details in extended objects (for example, on the disks of the Moon and planets) and to separate closely spaced point objects - stars. The resolution directly depends on the diameter of the telescope objective: if the aperture is doubled, then the resolving power will also double.

The second factor that affects resolution is the quality of lenses and mirror surfaces. Optics manufacturing errors, incorrect assembly and alignment, glass defects, scratches, dust and dirt on the surface of optical elements - all this becomes a source of deterioration in resolving power telescope.

When observing extended objects such as the Moon and planets, along with magnification telescope growing visible size Images. In contrast, point objects (stars) at high magnifications take the form of disks surrounded by several concentric rings of decreasing brightness. A similar pattern, called diffraction pattern, is due to the wave nature of light. The diameter of the central disk, called the Airy circle, is inversely proportional to the aperture. telescope.

Since the real image of the star is drowned in the Airy circle, in practice the separation of a close binary is reduced to looking at the diffraction pattern of the system in an attempt to distinguish the Airy disks of two closely spaced stars. If we assume that both components of a binary system have the same magnitude, then the minimum angular distance (in arcseconds) at which these stars can still be separated in a given telescope is calculated by the formula: 116″/D, where D is the diameter of the lens telescope in millimeters. This resolving power formula is called the Dawes limit, after the name of the English astronomer who received it in the 19th century. Theoretical values ​​of resolving power for telescopes different diameters are shown in the summary table.

Penetrating power of the telescope

This is the minimum magnitude of stars, nebulae, galaxies that can be distinguished with this telescope.

The penetrating power of a telescope depends on two factors:

Astroclimate. This is a complex of the following characteristics of the atmosphere: wind strength, temperature and humidity fluctuations, atmospheric transparency, and more.

The location of the telescope is also one of the most important conditions affecting the penetrating power of telescopes. If you set up a telescope in a low-lying area, say at or below sea level, then the penetrating power will be very low. The higher the terrain on which the telescope is installed, the higher its penetrating power will be.

penetrating power telescope characterized by the limiting magnitude of the faintest stars that can be seen with this instrument in a perfectly dark sky. Limit magnitude (m) for telescope, whose objective diameter is D in millimeters, can be approximated by the following formula: m = 2.5 + 5 lg D.

Enlightenment of optics allows to increase penetrating ability telescope, while dust and dirt on the optics lowers it.

telescope luminosity

This parameter is characterized by the ratio of the lens diameter to its focal length (D/f). This value is called the relative aperture and is written as a fraction: 1:5, 1:7, 1:10, 1:15… : f/5, f/7, f/10, f/15… The larger the lens aperture telescope(or vice versa: the smaller the ratio of the focal length to the diameter of the lens), the higher its aperture.

Aperture telescope, first of all, is important for determining its suitability for photographic purposes - a faster instrument will allow you to take shorter exposures when photographing faint astronomical objects. Another advantage of high-aperture instruments is their greater compactness compared to conventional instruments (due to a shorter focus), and they are more suitable for observations at low magnifications (for the same reason). On the other hand, fast instruments are more difficult to manufacture and align, and are more susceptible to various optical aberrations.

Lens diameter, mm	Magnification range, times	Resolution, "	Penetrating ability, sv. led.
60	10 - 120	1.93	11.4
70	12 - 140	1.66	11.7
80	13 - 160	1.45	12
90	15 - 180	1.29	12.3
100	17 - 200	1.16	12.5
110	18 - 220	1.05	12.7
120	20 - 240	0.97	12.9
130	22 - 260	0.89	13.1
150	25 - 300	0.77	13.4
200	33 - 400	0.58	14
250	42 - 500	0.46	14.5
300	50 - 600	0.39	14.9

Which telescope to choose

1. A schoolchild of 8-10 years old who is interested in stars can be presented with an inexpensive and easy-to-use refractor telescope from a special children's series with an aperture of 70 mm or more on an azimuthal mount. And an additional adapter for the camera will allow him to take beautiful pictures of the Moon and ground objects.
2. It is better for a novice night sky explorer living in the city to buy a short-focus refractor with an aperture of 70-90 mm on an azimuth stand. If it is possible to observe stars somewhere "in the field", you can fork out for a 110-250 mm reflector with a Dobson mount included.
3. If your dream is to study distant galaxies and nebulae, get a reflector with a lens diameter of 250 mm or more, complete with an azimuth stand.
4. Travelers or those who intend to frequently transport their telescope will need a light and reliable lens-reflex apparatus equipped with a Dobson system or an azimuth stand.
5. Experienced astrophotographers cannot do without a catadioptric telescope with a maximum aperture (400 mm) and a long focus of 1000 mm. It is better to choose an equatorial mount with an automatic drive.

How much does a telescope cost

1. A refractor on an azimuthal mount can be purchased at a price of 3,500 to 25,000 rubles. The cost will depend on the technical characteristics of the optics and the functionality of the device.

2. Mirror reflector on an equatorial stand will cost you from 14 to 55 thousand rubles.

3. For a professional and powerful catadioptric, you will have to pay 18-130 thousand.

> Types of telescopes

All optical telescopes are grouped according to the type of light-collecting element into mirror, lens and combined. Each type of telescope has its advantages and disadvantages, therefore, when choosing optics, the following factors should be taken into account: the conditions and objectives of observation, requirements for weight and mobility, price, and the level of aberration. Let's characterize the most popular types of telescopes.

Refractors (lens telescopes)

Refractors These are the first telescopes invented by man. In such a telescope, a biconvex lens is responsible for collecting light, which acts as an objective. Its action is based on the main property of convex lenses - the refraction of light rays and their collection in focus. Hence the name - refractors (from the Latin refract - to refract).

It was created in 1609. It used two lenses, with the help of which the maximum amount of starlight was collected. The first lens, which acted as a lens, was convex and served to collect and focus light at a certain distance. The second lens, which played the role of an eyepiece, was concave and was used to turn the descending light beam into a parallel one. With Galileo's system, you can get a straight, upside-down image, the quality of which suffers greatly from chromatic aberration. The effect of chromatic aberration can be seen as a false painting of the details and edges of the object.

Kepler refractor- a more advanced system that was created in 1611. Here, a convex lens was used as an eyepiece, in which the front focus was combined with the back focus of the objective lens. From this, the final image was inverted, which is not essential for astronomical research. The main advantage of the new system is the ability to install a measuring grid inside the pipe at the focal point.

This scheme was also characterized by chromatic aberration, however, the effect of it could be leveled by increasing the focal length. That is why the telescopes of that time had a huge focal length with a tube of the appropriate size, which caused serious difficulties in conducting astronomical research.

At the beginning of the 18th century, it appeared, which is still popular today. The lens of this device is made of two lenses made of different types of glass. One lens is converging, the other is diverging. This structure can greatly reduce chromatic and spherical aberrations. And the body of the telescope remains very compact. Today, apochromatic refractors have been created in which the influence of chromatic aberration is reduced to a possible minimum.

Advantages of refractors:

• Simple structure, easy operation, reliable;
• Fast thermal stabilization;
• Undemanding to professional service;
• Ideal for exploring planets, moon, double stars;
• Excellent color reproduction in apochromatic performance, good - in achromatic;
• System without central shielding from a diagonal or secondary mirror. Hence the high contrast of the image;
• Lack of air flow in the pipe, protection of optics from dirt and dust;
• One-piece lens construction requiring no adjustments by the astronomer.

Disadvantages of refractors:

• High price;
• Great weight and dimensions;
• Small practical aperture diameter;
• Limited in the study of dim and small objects in deep space.

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The name of mirror telescopes is reflectors comes from the Latin word reflectio - to reflect. This device is a telescope with a lens, which is a concave mirror. Its task is to collect starlight at a single point. By placing an eyepiece at this point, you can see the image.

One of the first reflectors ( Gregory's telescope) was coined in 1663. This telescope with a parabolic mirror was completely free from chromatic and spherical aberrations. The light collected by the mirror was reflected from a small oval mirror, which was fixed in front of the main one, in which there was a small hole for the output of the light beam.

Newton was completely disappointed in refracting telescopes, so one of his main developments was a reflecting telescope based on a metal primary mirror. It equally reflected light with different wavelengths, and the spherical shape of the mirror made the device more accessible even for self-production.

In 1672, astronomer Lauren Cassegrain proposed a scheme for a telescope that outwardly resembled the famous Gregory reflector. But the improved model had several major differences, the main of which was a convex hyperbolic secondary mirror, which made the telescope more compact and minimized the central shielding. However, the traditional Cassegrain reflector turned out to be low-tech for mass production. Mirrors with complex surfaces and uncorrected coma aberration are the main reasons for this unpopularity. However, modifications of this telescope are used today around the world. For example, the Ritchey-Chrétien telescope and the mass of optical instruments based on the system Schmidt-Cassegrain and Maksutov-Cassegrain.

Today, the name "reflector" is commonly understood as a Newtonian telescope. Its main characteristics are a small spherical aberration, the absence of any chromatism, as well as non-isoplanatism - a manifestation of coma near the axis, which is associated with the unevenness of individual annular aperture zones. Because of this, the star in the telescope does not look like a circle, but like a projection of a cone. At the same time, its blunt rounded part is turned from the center to the side, and the sharp one, on the contrary, to the center. To correct the coma effect, lens correctors are used, which should be fixed in front of the camera or eyepiece.

"Newtons" are often performed on a Dobson mount, which is practical and compact in size. This makes the telescope a very portable device, despite the size of the aperture.

Advantages of reflectors:

Affordable price;

• Mobility and compactness;
• High efficiency when observing dim objects in deep space: nebulae, galaxies, star clusters;

The brightest and sharpest images with minimal distortion.

Chromatic aberration is reduced to zero.

Disadvantages of reflectors:

• Stretch secondary mirror, central shielding. Hence the low contrast of the image;
• Thermal stabilization of a large glass mirror takes a long time;
• Open pipe without protection from heat and dust. Hence the poor image quality;
• Requires regular collimation and alignment, which may be lost during use or transport.

Catadioptric telescopes use both mirrors and lenses to correct aberration and build images. Two types of such telescopes are in great demand today: Schmidt-Cassegrain and Maksutov-Cassegrain.

Instrument design Schmidt-Cassegrain(SHK) consists of spherical primary and secondary mirrors. In this case, spherical aberration is corrected by a full-aperture Schmidt plate, which is installed at the pipe inlet. However, some residual aberrations in the form of coma and field curvature remain here. Their correction is possible by using lens correctors, which are especially relevant in astrophotography.

The main advantages of devices of this type relate to the minimum weight and short tube while maintaining an impressive aperture diameter and focal length. At the same time, these models are not characterized by extensions of the attachment of the secondary mirror, and the special design of the pipe excludes the penetration of air and dust into the interior.

System development Maksutov-Cassegrain(MK) belongs to the Soviet optical engineer D. Maksutov. The design of such a telescope is equipped with spherical mirrors, and a full-aperture lens corrector, which is a convex-concave lens - the meniscus, is responsible for the correction of aberrations. That is why such optical equipment is often called a meniscus reflector.

The advantages of MC include the ability to correct almost any aberration by selecting the main parameters. The only exception is higher order spherical aberration. All this makes the scheme popular among manufacturers and astronomy enthusiasts.

Indeed, ceteris paribus, the MC system gives better and clearer images than the SC scheme. However, larger MK telescopes have a longer thermal stabilization period, since the thick meniscus loses temperature much more slowly. In addition, MCs are more sensitive to the stiffness of the corrector mounting, so the telescope design is heavy. This is the reason for the high popularity of MC systems with small and medium apertures and SC systems with medium and large apertures.

In addition, Maksutov-Newton and Schmidt-Newton catadioptric systems have been developed, the design of which was created specifically for the correction of aberrations. They retained Newtonian dimensions, but their weight increased significantly. This is especially true for meniscus correctors.

Advantages

• Versatility. Can be used for both ground and space observations;
• Increased level of aberration correction;
• Protection against dust and heat flows;
• Compact dimensions;
• Affordable price.

Flawscatadioptric telescopes:

• Long period of thermal stabilization, which is especially important for telescopes with a meniscus corrector;
• The complexity of the design, which causes difficulties during installation and self-alignment.

Telescopes - types and device.

The main purpose of telescopes is to collect as much radiation from a celestial body as possible. This allows you to see dim objects. Secondarily, telescopes are used to view objects at a large angle, or, as they say, to increase. Resolution of small details is the third purpose of telescopes. The amount of light they collect and the available detail resolution is highly dependent on the area of ​​the main part of the telescope - its lens. Lenses are reflex and lens.

lens telescopes.

Lenses, one way or another, are always used in a telescope. But in refracting telescopes, the lens is the main part of the telescope - its lens. Remember that refraction is refraction. A lens lens refracts light rays and collects them at a point called the focus of the lens. At this point, an image of the object of study is built. To view it, use the second lens - the eyepiece. It is placed so that the foci of the eyepiece and objective coincide. Since people have different vision, the eyepiece is made movable so that it is possible to achieve a clear image. We call this sharpening. All telescopes have unpleasant features - aberrations. Aberrations are distortions that occur when light passes through optical system telescope. The main aberrations are associated with the imperfection of the lens. Lens telescopes (and telescopes in general) suffer from several aberrations. We will name only two of them. The first is due to the fact that rays of different wavelengths are refracted slightly differently. Because of this, there is one focus for blue rays, and another one for red rays, located further from the lens. Rays of other wavelengths are collected each in its place between these two foci. As a result, we see rainbow-colored images of objects. This aberration is called chromatic. The second strong aberration is the spherical aberration. It is related to the fact that the lens, the surface of which is part of the sphere, in fact, does not collect all the rays at one point. Rays coming at different distances from the center of the lens are collected at different points, due to which the image is fuzzy. This aberration would not exist if the lens had a paraboloid surface, but such a detail is difficult to manufacture. To reduce aberrations, complex, not at all two-lens systems are made. Additional parts are introduced to correct lens aberrations. For a long time holding the championship among the lens telescopes - the telescope of the Yerkes Observatory with a lens of 102 centimeters in diameter.

mirror telescopes.

In simple mirror telescopes, reflecting telescopes, the lens is a spherical mirror that collects light rays and reflects them with the help of an additional mirror towards the eyepiece - the lens at the focus of which the image is built. A reflex is a reflection. SLR telescopes do not suffer from chromatic aberration, since the light in the lens is not refracted. But reflectors have a more pronounced spherical aberration, which, by the way, greatly limits the field of view of the telescope. Mirror telescopes also use complex structures, mirror surfaces other than spherical, and so on.

Mirror telescopes are easier and cheaper to manufacture. That is why their production has been rapidly developing in recent decades, while new large lens telescopes have not been made for a very long time. The largest reflex telescope has a complex multi-mirror lens equivalent to an entire mirror 11 meters in diameter. The largest monolithic reflex lens has a size of just over 8 meters. The largest optical telescope in Russia is the 6-meter mirror telescope BTA (Large Azimuthal Telescope). Telescope for a long time was the largest in the world.

characteristics of telescopes.

Telescope magnification. The magnification of a telescope is equal to the ratio of the focal lengths of the objective and the eyepiece. If, say, the focal length of the lens is two meters, and the eyepiece is 5 cm, then the magnification of such a telescope will be 40 times. If you change the eyepiece, you can change the magnification. This is what astronomers do, after all, it’s not possible to change, in fact, a huge lens ?!

exit pupil. The image that the eyepiece builds for the eye can, in the general case, be either larger than the pupil of the eye, or smaller. If the image is larger, then part of the light will not enter the eye, thus, the telescope will not be used at 100%. This image is called the exit pupil and is calculated by the formula: p=D:W, where p is the exit pupil, D is the diameter of the objective, and W is the magnification of the telescope with this eyepiece. Assuming a pupil size of 5 mm, it is easy to calculate the minimum magnification that is reasonable to use with a given telescope objective. We get this limit for a lens of 15 cm: 30 times.

Resolution of telescopes

In view of the fact that light is a wave, and waves are characterized not only by refraction, but also by diffraction, no even the most perfect telescope gives an image of a point star in the form of a point. The ideal image of a star looks like a disk with several concentric (with a common center) rings, which are called diffraction rings. The size of the diffraction disk limits the resolution of the telescope. Everything that covers this disk with itself cannot be seen in this telescope. The angular size of the diffraction disk in arcseconds for a given telescope is determined from a simple relationship: r=14/D, where the diameter D of the objective is measured in centimeters. The fifteen-centimeter telescope mentioned just above has a maximum resolution of just under a second. It follows from the formula that the resolution of a telescope entirely depends on the diameter of its lens. Here is another reason for building the grandest telescopes possible.

Relative hole. The ratio of the lens diameter to its focal length is called aperture ratio. This parameter determines the luminosity of the telescope, i.e., roughly speaking, its ability to display objects as bright. Lenses with a relative aperture of 1:2 - 1:6 are called fast lenses. They are used to photograph objects that are weak in brightness, such as nebulae.

Telescope without an eye.

One of the most unreliable parts of a telescope has always been the observer's eye. Each person has his own eye, with its own characteristics. One eye sees more, the other less. Each eye sees colors differently. The human eye and its memory are not able to preserve the whole picture offered for contemplation by a telescope. Therefore, as soon as it became possible, astronomers began to replace the eye with instruments. If you connect a camera instead of an eyepiece, then the image obtained by the lens can be captured on a photographic plate or film. The photographic plate is capable of accumulating light radiation, and this is its undeniable and important advantage over the human eye. Long-exposure photographs are able to display incomparably more than a person can see through the same telescope. And of course, the photo will remain as a document, which can be repeatedly referred to later. Even more modern means are CCD cameras with polar charge coupling. These are light-sensitive microcircuits that replace a photographic plate and transmit the accumulated information to a computer, after which they can take a new picture. The spectra of stars and other objects are studied using spectrographs and spectrometers attached to the telescope. Not a single eye is able to distinguish colors and measure the distances between lines in the spectrum so clearly, as these devices easily do, which also save the image of the spectrum and its characteristics for subsequent studies. Finally, no one can look through two telescopes with one eye at the same time. Modern systems of two or more telescopes, united by one computer and separated, sometimes at distances of tens of meters, make it possible to achieve amazingly high resolutions. Such systems are called interferometers. An example of a system of 4 telescopes - VLT. It is no coincidence that we have combined four types of telescopes into one subsection. The Earth's atmosphere is reluctant to let the corresponding wavelengths of electromagnetic waves through, so telescopes for studying the sky in these ranges tend to be taken out into space. It is with the development of astronautics that the development of the ultraviolet, x-ray, gamma and infrared branches of astronomy is directly connected.

radio telescopes.

The most common objective of a radio telescope is a metal bowl of a paraboloid shape. The signal collected by it is received by an antenna located at the focus of the lens. The antenna is connected to a computer, which usually processes all the information, building images in conditional colors. A radio telescope, like a radio receiver, can only receive a certain wavelength at a time. In the book of B. A. Vorontsov-Velyaminov “Essays on the Universe” there is a very interesting illustration that is directly related to the subject of our conversation. In one observatory, guests were invited to come to the table and take a piece of paper from it. A person took a piece of paper and read something like this on the back: “By taking this piece of paper, you have expended more energy than all the radio telescopes of the world have received during the entire existence of radio astronomy.” If you have read this section (and you should), then you must remember that radio waves have the longest wavelengths of all types of electromagnetic radiation. This means that the photons corresponding to radio waves carry very little energy. To collect an acceptable amount of information about the luminaries in the radio beams, astronomers build huge telescopes. Hundreds of meters - this is the not-so-surprising milestone for lens diameters that has been achieved by modern science. Fortunately, everything in the world is interconnected. The construction of giant radio telescopes is not accompanied by the same difficulties in processing the surface of the lens, which are inevitable in the construction of optical telescopes. Permissible surface errors are proportional to the wavelength, therefore, sometimes, the metal bowls of radio telescopes are not a smooth surface, but simply a grating, and this does not affect the reception quality in any way. The long wavelength also allows the construction of grandiose interferometer systems. Sometimes telescopes from different continents participate in such projects. The projects include space-scale interferometers. If they come true, radio astronomy will reach unprecedented limits in the resolution of celestial objects. In addition to collecting the energy emitted by celestial bodies, radio telescopes can “illuminate” the surface of the bodies of the solar system with radio beams. A signal sent from, say, the Earth to the Moon will bounce off the surface of our satellite and be received by the same telescope that sent the signal. This research method is called radar. With the help of radar, you can learn a lot. For the first time, astronomers learned that Mercury rotates around its axis in this way. Distance to objects, speed of their movement and rotation, their relief, some data on chemical composition surfaces - these are the important information that can be clarified by radar methods. The most grandiose example of such studies is the complete mapping of the surface of Venus, carried out by AMS "Magellan" at the turn of the 80s and 90s. As you may know, this planet hides its surface from the human eye behind a dense atmosphere. Radio waves, on the other hand, pass through clouds unhindered. Now we know about the relief of Venus better than about the relief of the Earth (!), because on Earth the cover of the oceans prevents us from studying most of the solid surface of our planet. Alas, the speed of propagation of radio waves is great, but not unlimited. In addition, with the remoteness of the radio telescope from the object, the scattering of the sent and reflected signal increases. At a distance of Jupiter-Earth, the signal is already difficult to receive. Radar - by astronomical standards, a melee weapon.

infrared telescopes.

Infrared waves are heat. In order to register the heat of very distant objects, it is necessary to isolate the receiving device from the radiation of all the heat that is generated by nearby objects, including the telescope itself. Today, instruments for measuring infrared rays are placed in a vacuum and cooled with liquid helium. How do these devices work? Imagine a thin sheet of foil through which a current is passed. If the temperature of the foil changes, the resistance of the metal will change and, accordingly, the current through it. By measuring the current, one can determine the degree of heating of the foil. That is the principle. Only the surface of the foil, on which the rays from the object converge, is made black so that it absorbs heat better. We have already talked about the cooling of the entire device.

Infrared telescopes do not have the ability to optically perceive all wavelengths of the range at once. The device is usually made sensitive to some narrow parts of the spectrum. In this, infrared telescopes are similar to radio telescopes, receiving signals at only one wavelength. Similar is the construction of an image of an object in rays invisible to the eye in conditional colors. Often in infrared photographs, shades of red are used to characterize the intensity of radiation of one or another part of the image. Therefore, if you see a photo in which there is an abundance of red, know: most likely, this photo was taken in thermal rays. One and the same telescope may well be both optical and infrared in different time. An example is the Hubble telescope. In many ways, the design of infrared telescopes themselves is similar to the design of optical mirror telescopes. Most of thermal rays can be reflected by a conventional telescopic lens and focused at one point, where the device that measures heat is located. There are also infrared filters that allow only heat rays to pass through. Photographs are taken with these filters.

ultraviolet telescopes.

Photographic film, especially if it is specially made for this purpose, can also be exposed to ultraviolet rays. Therefore, there is no fundamental problem in photographing ultraviolet images. In addition, in a significant part of the ultraviolet range, it is possible to receive systems with a mirror lens and a recording device. Ultraviolet telescopes are similar in design to infrared or optical telescopes. The use of filters allows you to highlight the radiation of certain parts of the range. Photons of small wavelengths (less than 2,000 A) are already registered in ways similar to registration x-ray radiation.

x-ray telescopes.

High-energy photons, which include X-ray photons, are already penetrating all kinds of mirror lens systems. Registration of such waves by the forces of counters elementary particles such as a Geiger counter. A particle entering such a device causes a short-term current pulse, which is recorded. Astronomers faced very big problems in order to achieve a high resolution of the telescope despite the complexity of the process of registering large fluxes of X-ray photons. But today, the resolution of X-ray telescopes is no longer a few degrees, as it used to be, but only 1 '.

Gamma-ray telescopes.

Gamma photons are even more energetic than X-ray photons. They are also registered by special counter devices, only of a different design. Alas, the resolution of gamma-ray telescopes does not exceed two or three degrees. Gamma-ray telescopes today register the very presence and approximate direction to the so-called gamma-ray flares - powerful bursts of gamma radiation, the causes of which have not yet been found. The location of the flare can be more or less accurately indicated by the simultaneous observation of the flare by two or three gamma-ray telescopes. The joint use of gamma-ray telescopes and telescopes that receive other types of radiation has helped in recent years to identify some gamma-ray bursts with one or another visible object.

Observations are the fundamental measurements of astronomy as a science. They are compared with data and theories generated in laboratories by astrophysicists and other physicists to test provable predictions.

Astronomers are in a unique position among scientists in that they cannot conduct experiments directly on the subjects of their research. Astronomers have to wait for photons (and now other forms of non-electromagnetic radiation) for these radiations to pass through the Universe to Earth and be seen by a person using one of the devices.

The key to making discoveries is having the right telescope in the right place to witness these photons and their history.

For most of human history, astronomical observations have been made beyond what can be seen with the eyes.
Some basic knowledge of what telescopes are for fundamental astronomy or for personal observation will be discussed in this article. Detailed information about these devices is concentrated on https://www.4glaza.ru/katalog/teleskopy/veber/

The uniqueness of the instrument for observing celestial objects

For many years, telescopes have been used to observe celestial objects. These instruments for observing distant objects have changed our understanding and knowledge of objects in the universe. Scientists and engineers are conducting new developments based on measuring the parameters of the wavelength that came from celestial objects, with improved technology for creating many types of telescopes.

Exist different kinds of this instrument, from household optical instruments manufactured by Veber to the most sophisticated X-ray instruments manufactured for the Aeronautics and Space Administration of NASA, the European Space Agency ESA or the Russian Roscosmos. The study of the various stages of the stars in detail can be done with these instruments, which are used for specific purposes.

This article will deal with the question of what telescopes are, as well as the functions and their purpose for analyzing the signals of our Universe.

Story

Since the seventeenth century, sky observation devices have become one of the important tools for detecting unexpected phenomena in the universe.

The controversy between traditional geocentric astronomy and those who preferred the Copernican heliocentric system had a great influence on the discovery of the telescope.

Initially, the invention of the telescope was a prototype of modern scientific instruments, and not an invention of scientists. The instrument gave people the ability to observe things that mankind had never seen before, increasing human senses and knowledge of objects in outer space. Masters have created an instrument that we call a telescope. The use of convex and concave objects to increase and decrease has been known since antiquity.

In the West at the end of the thirteenth century lenses became popular. Galileo was the first to use a refractive instrument as an instrument for observing the planets, moons and stars in 1609. Galileo used the Greek term tele, meaning far, and skopene, meaning looking, for instruments for observing the sky. Galileo proved that the predicted heliocentric model of the solar system was correct. He demonstrated that Venus showed a complete set of phases similar to the Moon. Galileo's discovery also proved that Ptolemy's model was impossible from his observations.

Galileo's discoveries changed our understanding of the universe through his telescope observations. In addition, new objects in the sky were discovered when Galileo used an optical instrument to prove the heliocentric appearance.

Telescope types

Wavelengths or electromagnetic radiation from the objects of the universe are different. Therefore, devices for monitoring remote objects are classified by design. They come in optical, x-ray, infrared ranges, as well as radio telescopes.

Optical

Optical telescopes are the most common because they are primarily used to observe distant objects in the visible part of the electromagnetic spectrum of visible light. Because visible light can be observed from Earth, most optical telescopes can be mounted on the ground.

Some atmospheric distortions can cause observations to be inaccurate for professionals.

X-ray

Emissions from distant objects and shorter wavelengths are detected using X-ray telescopes located on spacecraft. Their location on spacecraft is due to the fact that the atmosphere is opaque and therefore blocks any gamma rays, x-rays, and ultraviolet light can only be used in space, so there are no x-ray telescopes located on the ground.

radio telescopes

Other common types of telescopes that can be installed on Earth are radio telescopes, which are used for radio astronomy. Because they can receive radio waves from the universe, the antennas are open and relatively large. Because the atmosphere does not block radio waves, the radio telescope does not need to be placed above the Earth's atmosphere. A radio telescope can be used to observe objects such as quasars. To determine the cosmological redshift, one can study quasars and galaxies using spectroscopy. This helps to show the structure of the universe because the redshift is proportional to the distance.

Optical and radio telescopes are often located in mountains or outside urban areas because electromagnetic and light pollution from cities can affect the results of observations.

So, for example, in order not to interfere with the observation used by radio telescopes in the highlands of New Mexico, the United States built a lot of radio telescopes, which are used mainly to observe protoplanetary disks around young stars and black holes. This complex for the observation of the Universe was specially created outside the cities to avoid the influence during observation during the study of many astronomical objects.

Telescopes on satellites

Scientists have used ground-based telescopes to see visible light and radio waves from the star.
To study the Universe at all wavelengths and without blurring and darkening the Earth's atmosphere, scientists use satellites with telescopes.

Many objects located on different stages developments in the Universe emit electromagnetic waves, so telescopes of various types can provide images of these objects. Scientists can study radio waves from young stars to see star birth or star death when X-ray machines are used because these stars often emit X-rays. Ground-based complexes in this range introduce image distortions, and it is impossible to study large-scale images of galaxies.

The Hubble Space Observatory since 1991 is another typical example that can study the region of the sky in depth to reveal galaxies on early stages their evolution. It can collect more accurate and detailed images without the absence of atmospheric distortion.

Another example is NASA's Chandra Space Observatory from 1999. The Chandra satellite observatory has mapped the hot gas in galaxy clusters and is conducting research on black holes throughout the universe.

The Chandra Observatory provided a detailed study of the X-ray sky. These data are used to study dark energy and dark matter. Since dark energy and matter do not emit any radiation, observation devices can only partially help in the study, because they cannot directly observe the dark components of the universe. To study these objects, scientists have built a number of new detectors. The study of dark energy and dark matter may be possible by combining these new detectors in conjunction with telescopes.

conclusions

In the conclusions about what telescopes are, we can note the various types of this instrument, which provide numerous ways to study stars, planets and objects in the Universe.

There are telescopes from inexpensive home brand Veber to the most complex space-based ones.

Various kinds of telescopes have been developed to observe stars at various wavelengths throughout the universe. Telescopes vary in their functional applications in astronomy, although some objects like dark energy and dark matter cannot be directly observed. New technologies in the future will create better devices and tools for scientists to discover unknown objects in our universe.

Thus, a summary of what telescopes are for research and discovery in the Universe for present and future generations is presented.