Space nebulae. Nebula types

The word "nebula" is based on the Latin word "cloud". Indeed, it represents cosmic clouds, woven from dust and gas, which float in space. If there is more than one, then we are talking about nebulae.
This is the main building block in which contains the elements used to create stars and entire star systems. In addition, they are rightfully considered the most beautiful objects, glowing with a wealth of color shades and light swirls.

Do you know the brightest among the nebulae?

This is the Orion Nebula, located in the constellation of the same name. She is one of the brightest and most famous.
It is the stars located inside such a gas cloud that color it with beautiful shades of color - red, blue, green. It all depends on the combination of various elements that are inside such a nebula. The vast majority of them are:
- hydrogen 90%;
- helium 10%;
- 0.1% account for such heavy elements as nitrogen, carbon, potassium, magnesium, calcium, iron. Such clouds with matter are quite large. In fact, these are the largest galactic objects. Most of them are tens, and in some cases hundreds of light-years across.
Nebulae were divided into 5 categories, which are the main ones:
emission;
reflective;
dark;
planetary;
supernova remnants.
The first two categories in their own way appearance very indistinct, lacking any discernible form or structure. They are also called diffuse.

Main types of nebulae

emission nebula

This is a high temperature gas cloud. The stars illuminate the atoms of the cloud with UV radiation. Since they fall then to the lower energy level, then radiation occurs, resembling the process of the appearance of neon light - the nebula begins to glow. The abundance of hydrogen fills them with red color, additional shades (blue and green colors) can produce atoms of other elements. Although the most common is almost always hydrogen. An example of such a nebula is the Orion Nebula (M42).

reflection nebula

Its difference from the emission one is that it does not emit its own radiation. This dust-gas cloud only contributes to the reflection of the light energy of neighboring nebulae or a group of several stars. Most often located in places where stars form. The presence of a bluish tint is achieved by diffused light, because it is blue that can be scattered as efficiently as possible. great example serves as M20 - a tripartite nebula located in Sagittarius.

dark nebula

A cloud of dust that blocks light from objects behind it. Reminds reflective, according to its composition. The difference is the location of the light source. Usually a dark nebula is observed together with reflection and emission nebulae.
Perhaps the most famous example is the Horsehead Nebula, located in the constellation Orion. It is a dark area of ​​dust shaped like a horse's head, blocking light from the much larger emission behind it.

planetary nebula

This is a shell of gas that is "born" by a star approaching the end of its life cycle. Such a name is slightly misleading, because in reality they have nothing in common with any planets. They owe their name to a rounded shape, reminiscent of the outlines of the planets. The outer gaseous shell is most often illuminated by the remnants of stars preserved in the center.
The best example is M57, the Ring Nebula in the constellation Lyra.

supernova remnant

They are created after the end of the life of stars as a result of a massive explosion, better known as a supernova, as a result of which most of stellar matter is carried away into space. Clouds of matter begin to glow along with the remnants of the star that gave birth to them.
The best demonstration of a similar remnant of M1 supernovae is the Crab Nebula, located in the constellation Taurus.

Looking from the depths of space, mysterious objects have long attracted the interest of people watching the sky. Even the ancient Greek scientist Hipparchus in his catalog noted the presence of several foggy objects in the night sky. His colleague Ptolemy added five more nebulae to the list. In the 17th century, Galileo invented the telescope and with its help he was able to see the nebulae of Orion and Andromeda. Since then, as telescopes and other instruments have improved, new discoveries have begun in outer space. And nebulae were classified as a separate class of stellar objects.

Over time, there were a lot of known nebulae. They began to interfere with scientists and astronomers in search of new objects. AT late XVIII century, studying certain objects - comets, Charles Messier compiled a "catalog of diffuse stationary objects" that looked like comets. But due to the lack of sufficient technical support, this catalog includes both nebulae and galaxies, along with globular star clusters.

Just as telescopes improved, so did astronomy itself. The concept of "nebula" took on new colors and was constantly refined. Some types of nebulae were identified as star clusters, some were classified as absorbing, and in the 20s of the last century, Hubble was able to establish the nature of nebulae and highlight regions of galaxies.

The portal site will tell about theories of the origin of nebulae, their approximate number, types and distance from our planet. The portal operates purely scientifically proven facts and the most popular ideas.

Classification and types of nebulae on the portal website

The primary principle by which nebulae are classified is whether they absorb or scatter (emit) light. This criterion divides nebulae into light and dark. The radiation of light depends on their origin. And the sources of energy that excite their radiation depend on their own nature. Very often, not one, but two radiation mechanisms can operate in a nebula. Dark ones can only be seen through the absorption of radiation sources located behind them.

But if the first principle of classification is accurate, then the second (the division of nebulae into dusty and gaseous) is a conditional principle. Each nebula contains dust and gas. This division is due to different mechanisms of radiation and methods of observation. The presence of dust is best observed when the radiation is absorbed by dark nebulae, which are located behind the sources. The intrinsic radiation of the gaseous components of a nebula is seen when it is ionized by ultraviolet light or when the interstellar medium is heated. The latter process is possible after a wave hits it, which was formed after the explosion of a supernova.

The dark nebula is represented as a dense, most often molecular cloud of interstellar dust and gas. By absorbing light, the cloud becomes opaque. Most often, dark nebulae are seen against a background of light ones. It is extremely rare for scientists to notice them against the background Milky Way. They are called giant globules.

The absorption of light Av in the dark ones varies within wide limits. It can reach indicators: from 1–10 m to 10–100 m. The structure of nebulae with high absorption can only be studied using the methods of submillimeter astronomy and radio astronomy, when observing infrared radiation and molecular radio lines. Individual seals are often found in the nebula itself, with an Av value of up to 10,000 m. According to the theories of advanced astrophysicists, stars form there.

In the translucent parts of nebulae, a fibrous structure is clearly visible in the optical range. The general elongation and fibers are associated with the presence of magnetic fields, which hinder the movement of matter across magnetohydrodynamic instabilities and lines of force. This connection is due to the fact that the dust particles are charged with electricity.

Another striking type of nebula is the reflection nebula. These are gas and dust clouds illuminated by stars. If the stars are located in or near an interstellar cloud, but not very hot in order to reduce the amount of hydrogen around them, then the main source of optical radiation from the nebula itself becomes the light of stars scattered by interstellar dust. A striking example of this phenomenon is around the stars of the Pleiades.

Most of the reflection nebulae are located near the plane of the Milky Way. In some cases, the presence of such nebulae is observed at high galactic latitudes. These molecular clouds are different sizes, shape, density and mass and are illuminated by the combined radiation of the stars of the Milky Way. They are difficult to study because the surface brightness is very low. Sometimes, appearing on images of galaxies, non-existent details are visible in the photographs - jumpers, tails, etc.

A small part of the reflection nebulae has a comet-like appearance. They are called comets. In the name of such a nebula, as a rule, there is a variable star of the Taurus type. It illuminates the nebula. They are variable in brightness and are small in size, about hundredths of a parsec.

The light echo is the rarest type of reflection nebula. A striking example is the resulting flash new star in the constellation Perseus. This flash illuminated the dust, causing the resulting nebula to be visible for several years. And while in space, she moved at the speed of light. In addition to light echoes, gaseous nebulae are formed after such incidents.

Most reflection nebulae have a fine-fibrous structure, that is, a system of almost parallel filaments. Their thickness can reach several hundredths of a parsec. These fibers result from penetration magnetic field into the flute instability of the nebula. Fibers of dust and gas push apart lines of force in a magnetic field and seep between them.

Dust properties such as albedo, shape, grain orientation, scattering indicator, and size have enabled scientists and astronauts to study the distribution of light polarization and brightness across the surface of reflection nebulae.

Radiation-ionized nebulae are patches of interstellar gas that are highly ionized by stellar radiation. This radiation can also come from other sources. Most of all, such nebulae are studied in regions of ionized hydrogen, as a rule, this is the H II zone. In such zones, the matter is completely ionized. Its temperature is about 104 K. It heats up due to internal ultraviolet radiation. Inside the H II zones, stellar radiation in the Lyman continuum transforms into subordinate serial radiation (corresponding to the Rosseland theorem). Because of this, the spectrum of nebulae contains bright lines of the Belmer series and Lyman-alpha lines.

These nebulae also include zones of ionized carbon - C II. The carbon in them is completely ionized by starlight. Zones C II, as a rule, are located around zones H II. They are produced due to the low ionization potential of carbon compared to hydrogen. They can also form around stars with a high spectral type in the densities of the interstellar medium. Nebulae ionized by radiation also arise around strong X-ray sources. They have higher temperatures than in the H II zones, and a relatively high degree of ionization.

Planetary nebulae are the most common type of emission nebulae. They're made to expire upper layers stellar atmospheres. Such a nebula glows and expands in the optical range. They were first discovered in the 17th century by Herschel and called them that because of their resemblance to the disks of the planets. But not all planetary nebulae are disk-shaped; some are rounded rings. Inside such nebulae, a fine structure is observed in the form of spirals, jets, and small globules. Such nebulae expand at a speed of 20 km/s, and their mass is equal to 0.1 solar masses. They live for about 10 thousand years.

The portal site provides only verified and up-to-date information. We will take you to the mysterious world of space. And thanks to astronomers and astrophysicists, nebulae are no longer such a huge mystery as they used to be.

In addition to the usual, long-lived, foggy formations, there are short-term ones created by shock waves. They disappear when the kinetic energy of the moving gas disappears. There are several sources for the occurrence of such shock waves. Most often - this is the result of the explosion of a star. Less often - stellar wind, flashes of new and supernovae. In any case, there is one source of ejection of such matter - a star. Nebulae of this origin have the shape of an expanding shell or the shape of a sphere. The substance that was ejected as a result of the explosion can have different speeds from hundreds to thousands of kilometers per second, because of this, the temperature of the gas behind the shock wave reaches not millions, but billions of degrees.

Gas heated to enormous temperatures emits radiation in the X-ray range both in spectral lines and in the continuous spectrum. It glows weakly in spectral optical lines. Upon encountering the inhomogeneity of the interstellar medium, the shock wave bends around the seals. Inside the seal itself, its own shock wave propagates. It also causes radiation in the lines of the spectrum of the optical range. As a result, bright fibers are created that are perfectly visible in photographs.

The brightest post-shock nebulae are created by supernova explosions. They are called remnants of starbursts. They play an important role in shaping the shape of the interstellar gas. They are characterized by small size, weakness and fragility.

There is another type of nebulae. This type is also created after the appearance of the shock wave. But the main reason is the stellar wind from the Wolf-Rayet stars. Wolf stars have a fairly powerful wind mass flow and outflow velocity. They form medium-sized nebulae with very bright filaments. Comparing them with the remnants of supernova explosions, scientists argue that the radio emission of such nebulae has a thermal nature. The nebulae that are located around the Wolf stars do not live long. Their existence directly depends on the duration of the star's presence in the stage of the Wolf-Rayet star.

Absolutely similar nebulae are found around O-stars. These are very bright hot stars that belong to the spectral class O. They have a strong stellar wind. Unlike the nebulae located around the Wolf-Rayet stars, O-star nebulae are less bright, but have much big sizes and duration of existence.

The most common nebulae are found in star-forming regions. Low-velocity shock waves are created in regions of the interstellar medium. This is where star formation takes place. Such a process entails heating the gas to hundreds and even thousands of degrees, partial destruction of molecules, heating of the dust itself, excitation molecular levels. Such shock waves look like elongated nebulae and, as a rule, glow in the infrared range. A striking example of this phenomenon is seen in the constellation of Orion.

Nebulae in space are one of the wonders of the universe, striking in their beauty. They are valuable not only visual appeal. The study of nebulae helps scientists clarify the laws of the functioning of the cosmos and its objects, correct theories about the development of the Universe and the life cycle of stars. Today we know a lot about these objects, but far from everything.

mixture of gas and dust

Enough long time, until the middle of the century before last, nebulae were considered to be at considerable distances from us. The use of a spectroscope in 1860 made it possible to establish that many of them are composed of gas and dust. The English astronomer W. Heggins found that the light from nebulae is different from the radiation coming from ordinary stars. The spectrum of the former contains bright colored lines interspersed with dark ones, while in the latter case no such lines are observed.

Further research has established that the nebulae of the Milky Way and other galaxies are mostly composed of a hot mixture of gas and dust. Similar cold formations are often encountered. Such clouds of interstellar gas are also referred to as nebulae.

Classification

Depending on the properties of the elements that make up the nebula, several types of them are distinguished. All of them are presented in large numbers in the vastness of space and are equally interesting for astronomers. Nebulae that emit light for one reason or another are usually called diffuse or bright. Opposite to them in the main parameter, of course, are designated as dark. Diffuse nebulae are of three types:

reflective;

emission;

supernova remnants.

Emission nebulae, in turn, are subdivided into regions of new star formation (H II) and planetary nebulae. All of these types are characterized by certain properties that make them unique and worthy of close study.

Star formation regions

All emission nebulae are clouds of luminous gas of various shapes. Their main element is hydrogen. Under the influence of a star located in the center of the nebula, it ionizes and collides with the atoms of the heavier components of the cloud. The result of these processes is a characteristic pinkish glow.

The Eagle Nebula, or M16, is an excellent example of this type of object. Here is a region of star formation, many young, as well as massive hot stars. The Eagle Nebula is home to a well-known patch of space, the Pillars of Creation. These gas clumps, formed under the influence of the stellar wind, are the star formation zone. The formation of luminaries here is caused by the compression of gas and dust columns under the action of gravity.

Scientists have recently learned that we will only be able to admire the Pillars of Creation for another thousand years. Then they will disappear. In fact, the destruction of the Pillars occurred approximately 6,000 years ago due to a supernova explosion. However, the light from this region of space has been coming to us for about seven thousand years, so the event calculated by astronomers for us is only a matter of the future.

planetary nebulae

The name of the next type of luminous gas and dust clouds was introduced by W. Herschel. A planetary nebula is the last stage in a star's life. The shells shed by the luminary form a characteristic pattern. The nebula resembles a disk that usually surrounds a planet when viewed through a small telescope. To date, more than a thousand such objects are known.

Planetary nebulae - part of the process of transformation into At the center of formation is a hot star, similar in its spectrum to class O luminaries. Its temperature reaches 125,000 K. Planetary nebulae are mostly relatively small in size - 0.05 parsec. Most of them are located in the center of our galaxy.

The mass of the gas envelope thrown off by the star is small. It is tenths of a similar parameter of the Sun. The mixture of gas and dust is moving away from the center of the nebula at a speed of up to 20 km/s. The shell exists for about 35 thousand years, and then becomes very rarefied and indistinguishable.

Peculiarities

A planetary nebula could be various shapes. Basically, one way or another, it is close to the ball. Distinguish nebulae round, ring-shaped, similar to dumbbells, irregular shape. The spectra of such space objects include the emission lines of the luminous gas and the central star, as well as sometimes the absorption lines from the spectrum of the star.

planetary nebula radiates great amount energy. It is much larger than that for the central star. The core of the formation emits ultraviolet rays due to its high temperature. They ionize gas atoms. The particles are heated, instead of ultraviolet, they begin to emit visible rays. Their spectrum contains emission lines that characterize the formation as a whole.

Nebula cat's eye

Nature is a master at creating unexpected and beautiful forms. Noteworthy in this respect is the planetary nebula, because of the similarity called the Cat's Eye (NGC 6543). It was discovered in 1786 and was the first to be identified by scientists as a cloud of luminous gas. The Cat's Eye Nebula is located in and has a very interesting complex structure.

It was formed about 100 years ago. Then the central star shed its shells and formed concentric lines of gas and dust, characteristic of the pattern of the object. To date, the mechanism of formation of the most expressive central structure of the nebula remains unclear. The appearance of such a pattern is well explained by the location of a double star in the core of the nebula. So far, however, there is no evidence to support this state of affairs.

The temperature of the halo of NGC 6543 is approximately 15,000 K. The core of the nebula is heated to 80,000 K. At the same time, the central star is several thousand times brighter than the Sun.

colossal explosion

Massive stars often end their life cycle impressive special effects. Huge in their power explosions lead to the loss of all external shells by the luminary. They move away from the center at a speed exceeding 10,000 km/s. The collision of a moving substance with a static one causes strong rise gas temperature. As a result, its particles begin to glow. Often, supernova remnants are not spherical formations, which seems logical, but the nebula itself. different shapes. This happens because the substance ejected at high speed unevenly forms clots and accumulations.

Traces of a thousand years ago

Perhaps the most famous supernova remnant is the Crab Nebula. The star that gave birth to her exploded almost a thousand years ago, in 1054. The exact date managed to establish according to the Chinese chronicles, where its flash in the sky is well described.

The characteristic pattern of the crab nebula is gas ejected by a supernova and not yet completely mixed with interstellar matter. The object is located at a distance of 3300 light years from us and is continuously expanding at a speed of 120 km / s.

In the center, the Crab Nebula contains a supernova remnant, a neutron star, which emits streams of electrons that are sources of continuous polarized radiation.

reflective nebulae

Another type of these space objects consists of a cold mixture of gas and dust, unable to emit light on its own. Reflection nebulae glow due to nearby objects. These may be stars or similar diffuse formations. The spectrum of scattered light remains the same as that of its sources, but blue light dominates for the observer.

A very interesting nebula of this type is associated with the star Merope. A luminary from the Pleiades cluster has been destroying a passing molecular cloud for several million years. As a result of the influence of the star, the particles of the nebula line up in a certain sequence and are pulled towards it. After some time (the exact time is unknown), Merope can completely destroy the cloud.

A dark horse

Diffuse formations are often contrasted with an absorbing nebula. The galaxy has many of them. These are very dense clouds of dust and gas that absorb light from the emission and reflection nebulae and stars behind them. These cold cosmic formations are mainly composed of hydrogen atoms, although heavier elements are also found in them.

A magnificent representative of this type is the nebula. It is located in the constellation Orion. The characteristic shape of the nebula, so similar to the head of a horse, was formed as a result of the influence of stellar wind and radiation. The object is clearly visible due to the fact that a bright emission formation serves as its background. At the same time, the Horsehead Nebula is only a small part of an extended absorbing cloud of dust and gas, almost invisible.

Thanks to the Hubble telescope, nebulae, including planetary ones, are familiar to a wide range of people today. Photographs of the areas of space where they are located impress to the depths of the soul and leave no one indifferent.

The emission line nebula and the emission nebula create their own glow. Hydrogen atoms come into activity due to the powerful ultraviolet light of the stars. The hydrogen then ionizes (loses an electron emitting a photon).

O-type stars can ionize gas within a radius of 350 light years. The M17 nebula was discovered by de Chezo in 1746 and rediscovered in 1764 by Charles Messier. It is in Sagittarius and is also called the Cygnus Nebula, Omega, Horseshoe and Lobster Nebula. Incredibly bright and its pink glow can be seen without the use of technology at low latitudes (apparent magnitude - 6). Inside are young stars that create the HII region. Ionized hydrogen is responsible for the red color.

Infrared light helps to find huge amounts of dust hinting at active star formation. Inside is a cluster of 30 stars, shaded by a nebula rubbing 40 light-years across. The total mass is 800 times greater than the sun.

M17 is 5500 light years away. Together with M16, it is located in one spiral arm of the Milky Way (Sagittarius-Kiel).

July 31st, 2010

Nebulae. Part I

Nebulae. Previously, astronomers used this name for any celestial objects that are stationary relative to the stars, which, in contrast to them, have a diffuse, blurred appearance, like a small cloud (the Latin term used in astronomy for "nebula" is the Latin term nebula means "cloud"). Over time, it turned out that some of them, for example, the nebula in Orion, are composed of interstellar gas and dust and belong to our Galaxy. Other "white" nebulae, as in Andromeda and Triangulum, turned out to be gigantic star systems similar to the Galaxy. Therefore, scientists came to the conclusion that nebula - an interstellar cloud, consisting of dust, gas and plasma, emitted by its radiation or absorption in comparison with the surrounding interstellar medium.

Nebula types . Nebulae are divided into the following main types: diffuse nebulae, or H II regions, such as the Orion Nebula; reflection nebulae, like the Merope nebula in the Pleiades; dark nebulae, like the Coal Sack, which are usually associated with molecular clouds; supernova remnants like the Reticulum Nebula in Cygnus; planetary nebulae, like the Ring in Lyra.

This is NGC 2174, a bright nebula in the constellation Orin.

NGC 2237 is an emission nebula in the constellation Monoceros. It is an area of ​​ionized hydrogen where star formation processes take place.

Crescent Nebula. Or another name - NGC 6888 (another designation - LBN 203) - an emission nebula in the constellation Cygnus.

The Medusa Nebula, usually subtle and dim, is captured in this beautiful false color telescopic image. In the sky, the nebula is located at the feet of the celestial Gemini, and on its sides are the stars μ and η Gemini. The Medusa Nebula itself in the picture is at the bottom right. It is like a luminous crescent of emission gas with dangling tentacles. The Medusa Nebula is part of supernova remnant IC 443, an expanding bubble left over from the explosion of a massive star. The first light from that explosion reached the Earth 30,000 years ago. Like its cosmic sister, the Crab Nebula, the remnant of IC 443 is home to a neutron star, the collapsed core of a star. The Medusa Nebula is 5,000 light-years away. The image covers an area of ​​300 light years. The rest of the field in the image is occupied by the emission nebula Sharpless 249.

The nebula in the constellation Toucan or NGC 346 belongs to the emission class, that is, it is a cloud of hot gas and plasma. Its length is about 200 light years. The reason for the high temperature of NGC 346 is a large number of young stars in the region. Most of the stars are only a few million years old. For comparison, the age of the Sun is about 4.5 billion years.

The Crab Nebula (M1, NGC 1952, colloquially "Crab") is a gaseous nebula in the constellation Taurus, which is the remnants of a supernova. Located at a distance of about 6500 light years from Earth, has a diameter of 6 light years and is expanding at a speed of 1000 km / s. At the center of the nebula is a neutron star.

NGC 1499 (also known as LBN 756, California Nebula) is an emission nebula in the constellation Perseus. It has a reddish color, and in shape resembles the outlines of the US state of California. The length of the nebula is about 100 light years, the distance from Earth is 1500 light years.

The Veil Nebula, also known as the Loop Nebula or the Fishing Net Nebula, is a diffuse nebula in the constellation Cygnus, a huge and relatively dim supernova remnant. The star exploded about 5000-8000 years ago, during which time the nebula covered an area of ​​3 degrees in the sky. The distance to it is estimated at 1400 light years. This nebula was discovered on September 5, 1784 by William Herschel.

One of several "dust columns" of the Eagle Nebula, which can be seen as an image mythical creature. It is about ten light years across.

The Eagle Nebula (also known as Messier Object 16, M16 or NGC 6611) is a young open star cluster in the constellation Serpens.

Dust columns in which new stars form in the Eagle Nebula. The picture was taken with the Hubble telescope.

NGC 281 (other designations - IC 11, LBN 616) is an emission nebula in the constellation Cassiopeia. It is an area of ​​ionized hydrogen, where processes of active star formation take place. It is located at a distance of about 10 thousand light years from Earth. For its shape, the nebula was named the Pac-Man Nebula in honor of the character of the arcade computer game of the same name. The nebula fluoresces with red light under the influence of ultraviolet radiation, the source of which is the hot young stars of the open cluster IC 1590. Dark dust structures are also present in the nebula.

You see a known shape in an unknown place! This emission nebula is widely known because it looks like one of the continents of the planet Earth - North America. To the right of the nebula North America, which is also designated NGC 7000, is the less bright Pelican Nebula. These two nebulae are about 50 light-years across and are about 1,500 light-years away from us. They are separated by a dark absorbing cloud.

The Orion Nebula (also known as Messier 42, M42, or NGC 1976) is a luminous greenish emission nebula located below Orion's Belt. It is the brightest diffuse nebula. " Great Nebula Orion, along with the Andromeda Nebula, the Pleiades and the Magellanic Clouds, is one of the most famous objects in deep space. This is perhaps the most attractive winter object in the northern sky for astronomy lovers. Few astronomical views are as exciting as this nearby stellar nursery known as the Orion Nebula. The glowing gas of the nebula surrounds hot young stars at the edge of a vast interstellar molecular cloud just 1,500 light-years away.

The Dumbbell Nebula (also known as Messier Object 27, M27, or NGC 6853) is a planetary nebula in the constellation Vulpecula, located 1250 light-years from Earth. Its age is estimated at 3,000 to 4,000 years. This planetary nebula is one of the most remarkable objects for amateur observations. M27 is large, relatively bright and easy to find. This photograph was taken on a computer using the narrow-band imaging method, when images taken by telescopes in different wavelength ranges are combined: visible, infrared, ultraviolet, etc.

The Eskimo Nebula was discovered by astronomer William Herschel in 1787. If you look at the NGC 2392 nebula from the surface of the Earth, then it looks like a human head, as if in a hood. If you look at the nebula from space, as the space telescope did. Hubble in 2000, after the update, it is a gas cloud of the most complex internal structure, over the structure of which scientists are still scratching their heads. The Eskimo Nebula belongs to the class of planetary nebulae, i.e. is a shell that 10 thousand years ago were the outer layers of a star like the Sun. The inner shells that are visible in the picture today were blown out by a powerful wind from a star located at the center of the nebula. The "hood" consists of many relatively dense gas filaments, which, as shown in the picture, glow orange in the nitrogen line. The Eskimo Nebula is located at a distance of 5 thousand light years from us, and it can be detected with a small telescope in the direction of the constellation Gemini.

Against the backdrop of a scattering of stars in the central part of the Milky Way and in the famous constellation of Ophiuchus, dark nebulae writhe. The S-shaped dark feature at the center of this wide-field image is called the Serpens Nebula.

The Carina Nebula is located in the southern constellation Carina at a distance of 6500-10000 sv from us. years. It is one of the brightest and largest diffuse nebulae in the sky. It has many massive stars and active star formation. This nebula contains an unusually high concentration of young massive stars, the result of an explosive star formation that occurred approximately 3 million years ago. The nebula contains more than a dozen large stars, the mass of which is 50-100 times the mass of our Sun. The brightest of them - Karina - in the near future should end its existence with a supernova explosion.

Blown by the wind from a massive star, this interstellar vision has a surprisingly familiar shape. Cataloged as NGC 7635, it is better known simply as the Bubble Nebula. Although this bubble, 10 light-years in diameter, looks elegant, it is evidence of very violent processes at work. Above and to the right of the center of the bubble is a bright, hot Wolf-Rayet star with a mass between 10 and 20 times that of the Sun. A strong stellar wind and powerful radiation from the star formed this structure from the glowing gas in the surrounding molecular cloud. The attention-grabbing Bubble Nebula lies just 11,000 light-years away in the constellation of Cassiopeia.

In the pictures: the region of the Trapezium cluster in the Orion Nebula, named after four the brightest stars, forming something close to a trapezoid. The left picture was taken in visible light, right - in infrared. In the left image, only ordinary stars are visible, not covered by dust clouds. Added to the right are stars inside gaseous dust clouds and about 50 faint objects called "brown dwarfs".

Based on materials from Astronet, Wikipedia and Spiritual and Philosophical Forum A108.