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).

Planetary nebulae are generated by dying stars. By astronomical standards, planetary nebulae are very short-lived phenomena: their lifetime is about ten thousand years. Therefore, astronomers know no more than one and a half thousand such objects in our galaxy.

The Silent Cosmic Flame of a Dying Star: Planetary Nebula NGC 6302

The magnificent planetary nebula "Snail" is one of the brightest and most beautiful.

The Cat's Eye Nebula, NGC 6543: fantastic gas and dust sculptures photographed by the Hubble Space Telescope.

Another false color photo of NGC 6543. The Cat's Eye Nebula is about 1000 years old. Its shape may indicate that it was formed from a binary star system.

The famous planetary nebula M57 in the constellation Lyra, or the Ring Nebula. Images like this show the complex structure of the nebula.

Another well-known example of a planetary nebula is MyCn18, an hourglass around a dying star.

The Medusa Nebula is a very old planetary nebula. It is located about 1500 light years from Earth in the constellation Gemini.

Nebula NGC 3132 is a lake of light.

The planetary nebula Abell 39 is almost perfectly spherical. Its diameter is almost 5 light years, and the thickness of the walls is a third of a light year. The Abell 39 nebula lies 7,000 light-years from Earth in the constellation Hercules.

When a star dies, it sheds its outer layers, which, dissipating in space, form a planetary nebula. Such nebulae are called planetary nebulae solely because in small telescopes they look like tiny and dim disks. Previously, many astronomers took them for distant planets, hence the name. But large and modern instruments show astronomers many interesting things. NGC 6369 is another example of a magnificent planetary nebula with rich structure.

The planetary nebula "Dumbbell" in the constellation Vulpecula is one of the brightest objects of its kind. The nebula was first discovered by the French astronomer Charles Messier, who included it in his catalog of nebulous objects at number 27. The distance to M27 is known only approximately and is about 1200 light years.

Planetary nebula NGC 2346

One of the latest photographs of the Space Telescope. Hubble Nebula "Necklace".

Eskimo Nebula or NGC 2392

Nebula "Spirograph"

The Jones 1 Nebula, also known as PK 104-29.1, is a very faint, ghost-like nebula in the constellation Pegasus. This image was taken in 2009 by the Mayall Telescope.

Planetary nebula "Turtle"

The Electric Ray Nebula or Hen-1357 is the youngest known planetary nebula.

The very unusual planetary nebula Sharpless 2-188 (Sh2-188). Having an almost spherical shape, the nebula glows unevenly. The brighter glow of the southeastern part (lower left) is due to the collision of gas with interstellar matter, which generated this shock wave. It is in this direction that the dead star that gave rise to the nebula is moving.
Sharpless 2-188 is located in the constellation Cassiopeia.

Twisted like a spiral galaxy, planetary nebula K 4-55.

The object Mz 3 is the planetary nebula "Ant". Image from the Hubble telescope.

Scattered light from the Boomerang Nebula. In 1995, astronomers using the Hubble telescope measured the temperature of matter inside this nebula. It turned out that the substance of the nebula is only 1 degree warmer than the absolute zero point. The Boomerang Nebula is one of the coldest places in the universe.

Nebula NGC 7662 or Blue Snowball.

Planetary nebula "Soap Bubble".

Planetary nebula NGC 5307 as seen by the Hubble Space Telescope

In the fifth article in the series "Observations of deep space objects" I will give you some tips for observing planetary nebulae. In the previous four articles, you learned how to observe globular, open star clusters, galaxies, and diffuse nebulae. All recommendations are preferred for telescopes with an aperture of 110 mm or more. For "planetaries" the lens diameter is better from 150 mm.

Almost all planetary nebulae have a very small angular size, which is comparable to the size of Jupiter (40″). The surface brightness of these nebulae is quite high. It is recommended to use a telescope magnification: 80x - 200x.

But there are planetary nebulae with low brightness, for them it makes no sense to use an eyepiece with a high magnification or a diverging Barlow lens, which gives a higher magnification. For such nebulae, it is difficult to find recommendations and give advice on the use of magnification, everything is very subjective and the reader will be able to choose (pick up) himself. Dim "planetary" include: M 27, M 76, M 97, NGC 4361).

Planetary nebula with low surface brightness

I remind you, when you have found the desired object for observation (in our case, a planetary nebula), follow the following instructions. It will help you learn and get as much information as possible in practice. Do not forget to keep notes, this will speed up your memorization process and will later be useful for comparing objects with others of the same type, as well as teach you to distinguish and notice the subtleties of each of the objects.

Observation of a planetary nebula

1. As always, we start with an estimate of the angular size of the desired object. For a better and more accurate estimate, compare it with the planet Jupiter, which can be seen at the same magnification.
2. What shape is the nebula? Hollow inside, round, oval, incomprehensible? Is it possible to see and give any information about the edges of the nebula? What are they?
3. Is the brightness evenly distributed from the center to the edges? Maybe a separate area is saturated, another is less, or some color is visible?
4. What is the overall color seen through a telescope? Is the nebula completely grey? Or maybe bluish gray? Is there a reddish tint?
5. Take a look around. What can you say about the stars behind the "planetary", around it? Are there any very bright ones?
6. What is the approximate brilliance of the object under study?
7. Lastly, when the eye and brain have learned enough information - determine what the nebula looks like? Is there a resemblance to any object?

And that's it... Take a few seconds off the telescope, let your eyes rest. Imagine in front of you what you have just observed. Look again through the eyepiece, fix it. Check your notes. If all is well, then observations of this planetary nebula can be completed and, after a short pause, switch to a new object.

Here are a few simple, but in my opinion very useful and necessary recommendations should be followed when observing planetary nebulae. Until new articles, take care of your eyes and don't miss a single cloudless starry night.

These mysterious objects, looking at people from the depths of space, have long attracted the attention of those for whom observing the sky has become a part of life. Even in the catalog of the ancient Greek scientist Hipparchus, several nebulous objects in the starry sky were noted. And his colleague, Ptolemy, added five more nebulae to his catalog to those already known. Before Galileo's invention of the telescope, not many objects of this type could be seen with the naked eye. But already in 1610, a primitive telescope designed by Galileo aimed at the sky discovered the Orion Nebula there. Two years later, the Andromeda Nebula was discovered. And since then, with the improvement of telescopes, more and more new discoveries have begun, which eventually led to the isolation of a special class of stellar objects - nebulae.

After some time, there were enough known nebulae that they began to interfere with the search for new objects, such as comets. And so, in 1784, the French astronomer Charles Messier, who was just looking for comets, compiled the world's first catalog of cosmic nebulae, which was published in several parts. In total, 110 at that time known objects of this class were included there.
When compiling the catalog, Messier gave them the numbers M1, M2 and so on, up to M110. Many objects in this catalog still bear this designation.

However, at that time it was not known that the nature of the various nebulae is completely different from each other. For astronomers, they were just hazy spots, different from ordinary stars.
Now, thanks to the achievements of astronomy, we know incomparably more about nebulae. What are these mysterious objects, and how do they differ from each other?

First of all, many will probably be surprised when they find out that there are not only bright nebulae. Today there are many objects known as dark nebulae. They are dense clouds of interstellar dust and gas that are opaque to light due to absorption by the dust contained in the nebula. Such nebulae stand out clearly against the background of the starry sky or against the background of light nebulae. A classic example of such a nebula is the Coalsack Nebula in the constellation of the Southern Cross. It often happens that such a nebula serves as material for the formation of new stars in its region due to the large amount of interstellar matter.

As for bright nebulae, they also contain both gas and dust. However, the glow of such a nebula can be caused by several factors. Firstly, this is the presence of a star inside such a nebula or next to it. In this case, if the star is not too hot, then the nebula glows due to the light reflected and scattered by the cosmic dust included in its composition. Such a nebula is called a reflection nebula. A classic example of such an object is the Pleiades cluster, perhaps known to everyone.

Ionized nebulae are another type of light nebula. Such nebulae are formed as a result of strong ionization of the interstellar gas included in their composition. The reason for this is the radiation of a nearby hot star or another object that is a source of powerful radiation, including ultraviolet and X-rays. Thus, bright ionized nebulae are found in the nuclei of active galaxies and quasars. A number of such nebulae, also known as Region H II, are sites of active star formation. Hot young stars forming inside it ionize the nebula with powerful ultraviolet radiation.

Another type of cosmic nebulae are planetary nebulae. These objects are formed as a result of the ejection of the outer shell by a giant star with a mass of 2.5 to 8 solar masses. Such a process occurs during a nova explosion (not to be confused with a supernova explosion, these are different things!), when part of the stellar matter is ejected into outer space. Such nebulae have the shape of a ring or disk, as well as a sphere (for New Stars).

A supernova explosion also leaves behind a luminous nebula heated during the explosion to several million degrees. These are much brighter bright nebulae than ordinary planetary nebulae. By cosmic standards, their life span is quite short - no more than 10 thousand years, after which they merge with the surrounding interstellar space.

A rarer and more exotic type of nebulae are the nebulae around Wolf-Rayet stars. These are stars with a very high temperature and luminosity, with powerful radiation and the speed of the outflow of stellar matter from their surface (over 1000 kilometers per second). Such stars ionize the interstellar gas within a radius of several parsecs. However, very few stars of this type are known (in our Galaxy - a little more than 230), so there are correspondingly few nebulae of this type.

As you can see, our knowledge of cosmic nebulae today is quite extensive, although, of course, there is still a lot of obscurity in the processes of their formation and life. However, this does not prevent us from admiring their beauty in the same way as our less knowledgeable ancestors did.

One of my favorite objects. And all the more it is a little surprising that such beauties are not given in the album. Therefore, I am replenishing (especially since I promised to continue about nebulae).

What is a planetary nebula? This is a star, called the core of the nebula, and the luminous gas envelope surrounding it. Planetary nebulae were discovered by W. Herschel around 1783. The name reflects their resemblance to the disks of the outer planets - Uranus, Neptune. Approximately 1500 planetary nebulae are known. With the development of observational technology, it became possible to see similar objects in the Magellanic Clouds, in the Andromeda Nebula, and in a number of other galaxies.

During their lifetime, stars continuously lose matter in the form of the so-called. stellar wind. Depending on the mass of the star and the evolutionary stage at which it is located, the rate of mass loss can be greater or less. Our Sun, for example, is now losing matter very slowly, which is typical of not very massive main sequence stars. However, even a weak solar wind leads to some consequences, for example, it turns out to be the cause of such a beautiful phenomenon as the aurora. In the future, the Sun will lose matter much more actively. The ejection of the red giant envelope corresponds to the loss of a sufficiently large mass in the form of a slow stellar wind. It is this substance that will make up the future nebula, and the appearance of the nebula depends on its structure. However, the ejected shell itself will not shine brightly: for the birth of a planetary nebula, a collision of two winds is necessary.
The scenario for the formation of a planetary nebula is as follows. At the beginning, the star must lose significant mass in the form of a slow stellar wind. This may be, for example, the discarded shell of a red giant (another variant is associated with evolution in a binary system). After shedding the shell from the star, a hot core remains. It becomes the source of a very fast stellar wind with a flow speed of about 1000 km per second. A fast wind overtakes a powerful slow stream, and their collision makes the substance glow, as if showing an already "woven" bizarre ligature.

Will our Sun ever present such a picture? Nebula Snail- a very close example of a planetary nebula that occurs at the end of the life path of a star like our Sun. The gas ejected into the surrounding space by the star gives the impression that we are looking at the curl of a spiral. The stellar core remaining in the center must eventually turn into a white dwarf. The central star emits intense radiation that causes the ejected gas to glow. The Helix Nebula is located in the constellation Aquarius and is designated in the catalog as NGC 7293. This nebula is 650 light years away from us, its size is 2.5 light years. The photo montage you see is based on the latest images from the Advanced Camera for Surveys (ACS) camera aboard the Hubble Space Telescope and wide-angle images from the Mosaic Camera on the 0.9-m telescope at Kit Peak Observatory. A close-up image of the inner edge of the Helix Nebula reveals a complex structure of gas formations of unknown origin.

Planetary Hourglass Nebula
This is an image of the young planetary nebula MyCn18, located approximately 8,000 light years away. years was obtained by the Wide Field Planetary Camera 2 aboard the space telescope. The image was synthesized from three different images taken in the red line of ionized nitrogen, the green line of hydrogen, and the blue line of doubly ionized oxygen.
Previous images taken from Earth show two crossed rings, but no details. According to one theory, the formation of such a shape is associated with a fast stellar wind inside a slowly expanding cloud, which has a greater density at the poles than at the equator. The space telescope also discovered other new unexpected properties in the structure of this nebula. For example, there are a pair of crossed rings in the central region and numerous arcs. These features can be satisfactorily explained by the presence of an invisible companion star.

The pictured planetary nebula, named Shapley 1 in honor of the famous astronomer Harlow Shapley, has a pronounced ring structure.

The very fact of the existence of one of the largest spheres in our Galaxy is a source of valuable information about the chemical composition of stars. planetary nebula Abell 39, which is now six light-years across, is the outer atmosphere of a solar-type star shed thousands of years ago. Abell 39's near-ideal spherical shape allowed astronomers to accurately estimate the ratio of absorbing and emitting matter in it. According to observations, the oxygen content in Abell 39 is about half that of the sun - a very interesting, although not surprising result, confirming the differences in the chemical composition of the two stars. The reason for the non-central position of the central star of the nebula (it is shifted by 0.1 light years) has not yet been established. The distance to Abell 39 is about 7000 light years, and the galaxies visible near and through the nebula are millions of light years away from us.

This planetary nebula with two bubbles, imaged by the space telescope. Hubble, beautifully "boils". Designated Hubble-5 this bipolar planetary nebula was formed by a hot particle wind emanating from the central star system. Hot gas expands into the surrounding interstellar medium in the form of inflating hot gas balls. A supersonic shock wave is formed at the boundary, which excites the gas. The gas glows when electrons recombine with atoms. In the picture, the colors correspond to the energy of the recombination radiation. This nebula is located at a distance of 2200 light years from Earth. At the center of the nebula is most likely a star like the Sun, which is slowly turning into a white dwarf.

Why is this "ant" so unlike a ball? After all, the planetary Nebula Mz3 is a shell thrown off by a star like our Sun, that is, an object, no doubt, spherical. Why, then, does the gas flowing from the star give rise to an antlike nebula, the shape of which has nothing to do with a ball? The reasons for this may be the extremely high - up to 1000 kilometers per second - the speed of the ejected gas; gigantic dimensions of the structure, reaching one light year; or the presence of a star located above the center of the nebula with a strong magnetic field. In the interior of Mz3, another star of lesser luminosity may also be hiding, which orbits a bright star at a very small distance from the latter. According to another hypothesis, the gas flows owe their direction to the rotation of the central star and its magnetic field. Astronomers hope that, thanks to the similarity of the central star to the Sun, the study of the history of this giant space ant will provide a glimpse into the future of the Sun and our Earth.

This planetary nebula is formed by a dying star that is shedding shells of glowing gas. The nebula is located at a distance of three thousand light years. In today's picture taken by the Space Telescope. Hubble, shows how complex the structure of the nebula is cat eye. Because of the complex structure seen in this image, astronomers suspect that the bright central object is a binary star.

Eskimo Nebula
This planetary nebula, first discovered by Herschel in 1787, was nicknamed the "Eskimo" because, from ground-based telescopes, it looked like a face surrounded by a fur hood. In the Hubble image, the "fur hood" appears as a disk of gas adorned with comet-like objects (see also the Helix Nebula) - elongated tails from a star.
"Face" also contains interesting details. The bright central region is nothing more than a bubble being blown into space by an intense wind of fast particles from the star.
The Eskimo Nebula began to form about 10,000 years ago. It consists of two elongated bubbles of material flowing in opposite directions. In the picture, one of the bubbles lies above the other, overlapping it. The origin of the comet-like features remains a mystery.
The Eskimo Nebula is located 5,000 light years from Earth in the constellation Geminga. The colors correspond to the glowing gases: nitrogen (red), hydrogen (green), oxygen (blue), and helium (purple).

This beautiful planetary nebula, cataloged as NGC 6369, was discovered by the 18th-century astronomer William Herschel when he explored the constellation Ophiuchus with a telescope. Round and planet-like, this relatively faint nebula has been popularly called the nebula. Little Ghost. The amazingly intricate details of NGC 6369's structure are visible in this remarkable color image, built from data taken by the Hubble Space Telescope. The main ring of the nebula is about a light year in diameter. The emission from ionized oxygen, hydrogen, and nitrogen atoms is shown in blue, green, and red, respectively. More than 2000 light-years away, the Little Ghost Nebula shows the future fate of our Sun, which should also form its own beautiful planetary nebula, but not before? than in about five billion years.

Planetary nebula IC 418, nicknamed Spirograph Nebula for its resemblance to the drawing tool of the same name, it is distinguished by a very unusual structure, the origin of which is still largely unsolved. The nebula may owe its bizarre shape to the chaotic wind emanating from a central variable star whose brightness changes in unpredictable ways over time intervals of just a few hours. At the same time, according to the available data, only a few million years ago, IC 418 was, apparently, a simple star similar to our Sun. Just a few thousand years ago, IC 418 was an ordinary red giant. However, after the depletion of nuclear fuel, the outer shell of the star began to expand, leaving behind a hot core, which fate prepared to turn into a white dwarf star located in the center of the image. Radiation from the central core excites the atoms in the nebula, causing them to glow. IC 418 is about 2,000 light-years away and has a diameter of 0.3 light-years. This false-color image taken recently by the Hubble Space Telescope clearly shows unusual details of the structure of the nebula.

In the center NGC 3132, an unusual and beautiful planetary nebula, is a double star. This nebula, also called Eight flare nebula or southern ring nebula, is due not to a bright, but to a faint star. The source of the glowing gas is the outer layers of a star similar to our Sun. The hot blue glow around the binary that you see in the figure is powered by the heat on the surface of the faint star. Initially, the planetary nebula became the object of research due to its unusual symmetrical shape. Subsequently, she attracted attention when she showed asymmetrical details. So far, neither the strange shape of the colder envelope nor the structure and origin of the cold dust lanes crossing the NGC 3132 nebula have been explained.

Is it true that stars look more beautiful when they die? planetary nebula M2-9, Nebula Butterfly, is located at a distance of 2100 light years from Earth. The wings of the nebula can tell us an unusual unfinished story. At the center of the nebula is a binary star system. The stars of this system move inside a disk of gas 10 times the diameter of Pluto's orbit. The ejected shell of a dying star breaks out of the disk, forming bipolar structures. Much remains unclear about the physical processes that form a planetary nebula.

How could a square nebula form around a round star? The study of a planetary nebula of the type IC 4406. There is reason to believe that the nebula IC 4406 has the shape of a hollow cylinder, and the square shape is due to the fact that we are looking at this cylinder from the side. If we looked at IC 4406 from the end, it could well look like the Ring Nebula. This color image is a combination of images taken by the Hubble Space Telescope. Hot gas flows out of the ends of the cylinder, filaments of dark dust and molecular gas fringing its walls. The star that is responsible for this piece of interstellar sculpture lies at the center of the planetary nebula. In a few million years, only a fading white dwarf will remain of IC 4406.

Rapidly expanding clouds of gas spell the end of the central star in the nebula Rotten Egg. Once there was a normal star, it used up its reserves of nuclear fuel, as a result, its central part shrank, forming a white dwarf. Part of the released energy causes the expansion of the outer shell of the star. In this case, the result is a photogenic protoplanetary nebula. When gas moving at a speed of a million kilometers per hour hits the surrounding interstellar gas, a supersonic shock wave is created in which ionized hydrogen and nitrogen glow blue. Previously, there were hypotheses about the complex structure of the shock front, but so far no such clear images have been obtained. Thick layers of gas and dust hide the dying central star. The Rotten Egg Nebula, also known as the Pumpkin Nebula and OH231.8+4.2, is likely to evolve into a bipolar planetary nebula within 1000 years. The nebula shown above is about 1.4 light-years across and is located 5,000 light-years away in the constellation of Puppis.

You can show pictures endlessly, especially since they are delightfully beautiful.