A galaxy is called a large formation of stars, gas, dust, which are held together by the force of gravity. These largest compounds in the universe can vary in shape and size. Most of the space objects are part of a particular galaxy. These are stars, planets, satellites, nebulae, black holes and asteroids. Some of the galaxies have a lot of invisible dark energy. Due to the fact that the galaxies are divided by empty space, they are figuratively called oases in the cosmic desert ..
| Elliptical galaxy | Spiral galaxy | Wrong galaxy | |
|---|---|---|---|
| Spheroidal component | Whole galaxy | there is | Very weak |
| Star disk | No or mild | Main component | Main component |
| Gas and dust disk | No | there is | there is |
| Spiral branches | No or only near the core | there is | No |
| Active nuclei | Meet | Meet | No |
| 20% | 55% | 5% |
Our galaxy
The closest star to us, the Sun, belongs to one billion stars in the Milky Way galaxy. Looking at the starry night sky, it is hard not to notice a wide stripe covered with stars. The ancient Greeks called the cluster of these stars the Galaxy.
If we had the opportunity to look at this stellar system from the side, we would have noticed an oblate ball, which contains over 150 billion stars. Our galaxy has dimensions that are hard to imagine. A ray of light travels from one side to the other for hundreds of thousands of Earth years! The center of our Galaxy is occupied by a core, from which huge spiral branches filled with stars extend. The distance from the Sun to the Galactic core is 30 thousand light years. The solar system is located at the edge of the Milky Way.
Stars in the Galaxy, despite the huge accumulation of cosmic bodies, are rare. For example, the distance between the nearest stars is tens of millions of times their diameters. This is not to say that the stars are scattered in the universe chaotically. Their location depends on the forces of gravity that hold the celestial body in a certain plane. Star systems with their own gravitational fields are called galaxies. In addition to stars, the galaxy includes gas and interstellar dust.
Composition of galaxies.
The universe is also made up of many other galaxies. The closest to us are distant at a distance of 150 thousand light years. They can be seen in the sky of the southern hemisphere as small foggy specks. They were first described by Pigafett, a member of the Magellanic expedition around the world. They entered science under the name of the Large and Small Magellanic Clouds.
The closest galaxy to us is the Andromeda Nebula. It has a very large size, so it is visible from the Earth with ordinary binoculars, and in clear weather - even with the naked eye.
The very structure of the galaxy resembles a giant convex spiral in space. The solar system is located on one of the spiral arms ¾ of the distance from the center. Everything in the galaxy revolves around the central core and obeys the force of its gravity. In 1962, astronomer Edwin Hubble classified galaxies based on their shape. The scientist divided all galaxies into elliptical, spiral, irregular and barred galaxies.
There are billions of galaxies in the part of the Universe accessible for astronomical research. Taken together, astronomers call them the Metagalaxy.
Universe Galaxies
Galaxies are represented by large groups of stars, gas, dust, held together by gravity. They can vary significantly in shape and size. Most of the space objects belong to a galaxy. These are black holes, asteroids, stars with satellites and planets, nebulae, neutron satellites.
Most of the galaxies in the universe contain vast amounts of invisible dark energy. Since the space between different galaxies is considered void, they are often called oases in the void of space. For example, a star named the Sun is one of the billions of stars in the Milky Way galaxy in our universe. At ¾ the distance from the center of this spiral is the solar system. In this galaxy, everything is constantly moving around the central core, which obeys its gravity. However, the nucleus also moves with the galaxy. Moreover, all galaxies move at super speeds.
Astronomer Edwin Hubble in 1962 logically classified the galaxies in the Universe, taking into account their shape. Now galaxies are divided into 4 main groups: elliptical, spiral, bar (bridge) and irregular galaxies.
What is the largest galaxy in our universe?
The largest galaxy in the universe is a super-giant lenticular galaxy located in the Abell 2029 cluster.
Spiral galaxies
They are galaxies that resemble a flat spiral disk with a bright center (core). The Milky Way is a typical spiral galaxy. Spiral galaxies are usually named with the letter S, they are divided into 4 subgroups: Sa, Sо, Sc and Sb. Galaxies belonging to the Sо group are distinguished by light cores that do not have spiral arms. As for the Sa galaxies, they are distinguished by dense spiral arms tightly wrapped around the central core. The arms of Sc and Sb galaxies rarely surround the core.
Messier spiral galaxies
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Barred galaxies
Barred galaxies are similar to spiral galaxies, but they still have one difference. In such galaxies, spirals begin not from the core, but from the barriers. About 1/3 of all galaxies fall into this category. They are usually denoted by the letters SB. In turn, they are divided into 3 subgroups Sbc, SBb, SBa. The difference between these three groups is determined by the shape and length of the bridges, from where, in fact, the spiral arms begin.
Messier barred spiral galaxies
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Elliptical galaxies
The shape of galaxies can vary from perfectly round to elongated oval. Their distinguishing feature is the absence of a bright central core. They are designated by the letter E and are divided into 6 subgroups (in shape). Such forms are designated from E0 to E7. The former are almost round in shape, while the E7 is characterized by an extremely elongated shape.
Messier elliptical galaxies
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Wrong galaxies
They do not have any pronounced structure or shape. Irregular galaxies are usually divided into 2 classes: IO and Im. The most common is the Im class of galaxies (it has only a slight hint of structure). In some cases, spiral remains can be traced. IO belongs to a class of galaxies that are chaotic in shape. Small and Large Magellanic Clouds are a prime example of the Im class.
Irregular Messier galaxies
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Table of characteristics of the main types of galaxies
| Elliptical galaxy | Spiral galaxy | Wrong galaxy | |
| Spheroidal component | Whole galaxy | there is | Very weak |
| Star disk | No or mild | Main component | Main component |
| Gas and dust disk | No | there is | there is |
| Spiral branches | No or only near the core | there is | No |
| Active nuclei | Meet | Meet | no |
| Percentage of the total number of galaxies | 20% | 55% | 5% |
Large portrait of galaxies
Not so long ago, astronomers began working on a joint project to identify the location of galaxies throughout the universe. Their task is to get a more detailed picture of the general structure and shape of the Universe on a large scale. Unfortunately, the scale of the universe is difficult for many people to understand. Take, for example, our galaxy, which consists of more than a hundred billion stars. There are billions of galaxies in the universe. Discovered distant galaxies, but we see their light as it was almost 9 billion years ago (we are separated by such a great distance).
Astronomers have learned that most galaxies belong to a certain group (they began to call it a "cluster"). The Milky Way is part of a cluster that, in turn, is made up of forty known galaxies. As a rule, most of these clusters are part of an even larger grouping called superclusters.
Our cluster is part of a supercluster commonly referred to as the Virgo cluster. Such a massive cluster consists of more than 2 thousand galaxies. As astronomers mapped these galaxies, superclusters began to take on specific shapes. Large superclusters have gathered around what appear to be giant bubbles or voids. What kind of structure it is, no one knows yet. We do not understand what may be inside these voids. According to the assumption, they can be filled with a certain type of dark matter unknown to scientists, or have empty space inside. It will take a long time before we know the nature of such voids.
Galactic Computing
Edwin Hubble is the founder of galactic exploration. He is the first to figure out how the exact distance to the galaxy can be calculated. In his research, he relied on the method of pulsating stars, which are better known as Cepheids. The scientist was able to notice the connection between the period that is needed to complete one pulsation of brightness and the energy that the star gives off. The results of his research have become a major breakthrough in the field of galactic research. In addition, he discovered that there is a correlation between the red spectrum emitted by the galaxy and the distance to it (Hubble constant).
Nowadays, astronomers can measure the distance and speed of a galaxy by measuring the amount of redshift in the spectrum. It is known that all galaxies in the Universe move away from each other. The further the galaxy is from the Earth, the greater its speed of movement.
To visualize this theory, it is enough to imagine yourself driving a car that moves at a speed of 50 km per hour. In front of you, a car is going faster by 50 km per hour, which means that its speed is 100 km per hour. There is another car in front of him, which moves faster by another 50 km per hour. Despite the fact that the speed of all 3 cars will be different by 50 km per hour, the first car is actually moving 100 km per hour faster from you. Since the red spectrum indicates the speed of the galaxy moving away from us, the following is obtained: the greater the redshift, the faster the galaxy moves, and the greater its distance from us.
We now have new tools to help scientists find new galaxies. Thanks to the Hubble Space Telescope, scientists have been able to see what previously could only dream of. The high power of this telescope provides good visibility of even small details in nearby galaxies and allows you to study more distant ones that were not known to anyone yet. Currently, new instruments for observing space are under development, and in the near future they will help to gain a deeper understanding of the structure of the universe.
Types of galaxies
- Spiral galaxies. In shape, they resemble a flat spiral disk with a pronounced center, the so-called nucleus. Our Milky Way galaxy falls into this category. In this section of the portal site you will find many different articles describing space objects in our Galaxy.
- Barred galaxies. They resemble spiral ones, only they differ from them in one significant difference. The spirals do not extend from the core, but from the so-called jumpers. A third of all galaxies in the Universe can be attributed to this category.
- Elliptical galaxies have a variety of shapes, from perfectly round to elongated oval. Compared with spirals, they lack a central, pronounced nucleus.
- Irregular galaxies have no characteristic shape or structure. They cannot be classified as any of the types listed above. There are far fewer irregular galaxies in the vastness of the universe.
Astronomers have recently launched a joint project to identify the location of all galaxies in the universe. Scientists hope to get a clearer picture of its structure on a large scale. The size of the universe is hard to gauge for human thinking and understanding. Our galaxy alone is a conjunction of hundreds of billions of stars. And there are billions of such galaxies. We can see the light from the detected distant galaxies, but do not even imply that we are looking into the past, because the light beam reaches us in tens of billions of years, such a great distance separates us.
Astronomers also link most galaxies to specific groups called clusters. Our Milky Way belongs to a cluster of 40 explored galaxies. Such clusters are combined into large groups called superclusters. The cluster with our galaxy is part of the Virgo supercluster. This giant cluster contains more than 2 thousand galaxies. After scientists began to map the distribution of these galaxies, superclusters took on certain shapes. Most galactic superclusters were surrounded by giant voids. Nobody knows what might be inside these voids: space like interplanetary space or a new form of matter. It will take a long time to solve this riddle.
Interaction of galaxies
No less interesting for scientists is the question of the interaction of galaxies as components of space systems. It's no secret that space objects are in constant motion. Galaxies are no exception to this rule. Some of the types of galaxies could cause collisions or mergers of two cosmic systems. If you understand how these space objects appear, large-scale changes become more understandable as a result of their interaction. During the collision of two space systems, a huge amount of energy is released. The meeting of two galaxies in the vastness of the Universe is an even more likely event than a collision of two stars. The collision of galaxies does not always end with an explosion. A small space system can freely pass by its larger counterpart, changing only slightly its structure.
Thus, the formation of formations occurs, similar in appearance to elongated corridors. In their composition, stars and gas zones are distinguished, new stars are often formed. There are times when galaxies do not collide, but only slightly touch each other. However, even this interaction triggers a chain of irreversible processes that lead to huge changes in the structure of both galaxies.
What is the future of our galaxy?
As scientists suggest, it is possible that in the distant future the Milky Way will be able to absorb a tiny satellite system, which is located at a distance of 50 light years from us. Studies show that this satellite has a long life potential, but when it collides with a giant neighbor, it is likely to end its separate existence. Astronomers also predict a collision between the Milky Way and the Andromeda Nebula. Galaxies move towards each other at the speed of light. Until a probable collision, wait about three billion Earth years. However, whether it will actually be now is difficult to speculate due to the lack of data on the motion of both space systems.
Description of galaxies onKvant. Space
The site portal will take you to the world of interesting and fascinating space. You will learn the nature of the construction of the Universe, get acquainted with the structure of the known large galaxies, their components. As we read articles about our galaxy, some of the phenomena that can be observed in the night sky become clearer to us.
All galaxies are at a great distance from Earth. Only three galaxies can be seen with the naked eye: the Large and Small Magellanic Clouds and the Andromeda Nebula. It is unrealistic to count all galaxies. Scientists estimate that their number is about 100 billion. The spatial arrangement of galaxies is uneven - one region can contain a huge number of them, in the second there will not be even a single small galaxy at all. Astronomers were unable to separate the image of galaxies from individual stars until the early 90s. At this time, there were about 30 galaxies with individual stars. All of them were assigned to the Local Group. In 1990, a majestic event in the development of astronomy as a science took place - the Hubble telescope was launched into Earth's orbit. It is this technique, as well as new ground-based 10-meter telescopes, that made it possible to see a significantly larger number of allowed galaxies.
Today, the "astronomical minds" of the world are racking their brains about the role of dark matter in the formation of galaxies, which manifests itself only in gravitational interaction. For example, in some large galaxies, it makes up about 90% of the total mass, while dwarf galaxies may not contain it at all.
Evolution of galaxies
Scientists believe that the emergence of galaxies is a natural stage in the evolution of the Universe, which took place under the influence of the forces of gravity. The formation of protoclusters in the primary matter began about 14 billion years ago. Further, under the influence of various dynamic processes, the selection of galactic groups took place. The abundance of forms of galaxies is explained by the variety of initial conditions in their formation.
The compression of the galaxy takes about 3 billion years. Over a given period of time, the gas cloud turns into a star system. Star formation occurs under the influence of the gravitational compression of gas clouds. After reaching a certain temperature and density in the center of the cloud, sufficient for the start of thermonuclear reactions, a new star is formed. Massive stars are formed from thermonuclear chemical elements that exceed helium in mass. These elements create a primary helium-hydrogen environment. During grandiose supernova explosions, elements heavier than iron are formed. It follows from this that the galaxy consists of two generations of stars. The first generation is the oldest stars, composed of helium, hydrogen, and very few heavy elements. Second-generation stars have a more prominent heavy element admixture, as they form from primordial gas enriched in heavy elements.
In modern astronomy, galaxies as cosmic structures have a separate place. The types of galaxies, the features of their interaction, similarities and differences are studied in detail, and a forecast of their future is made. This area contains many more incomprehensible things that require additional study. Modern science has solved many questions regarding the types of galaxy construction, but there are also many blank spots associated with the formation of these cosmic systems. The current pace of modernization of research technology, the development of new methodologies for the study of space bodies give hopes for a significant breakthrough in the future. One way or another, galaxies will always be at the center of scientific research. And this is based not only on human curiosity. Having received data on the patterns of development of space systems, we will be able to predict the future of our galaxy called the Milky Way.
The most interesting news, scientific, copyright articles about the study of galaxies will be provided by the portal site. Here you can find breathtaking videos, high-quality images from satellites and telescopes that will impress you. Dive into the world of unknown space with us!
Our planetary system of the planets and other objects known to us was formed during the formation of the Sun and the entire solar system. Likewise, during the process of forming other stars, some of them have formed objects that have formed their planetary system.
At the end of April 2013, it is already known about 692 such planetary systems around stars, in which the presence of planets of other solar systems is confirmed, and in 132 such systems there is more than one planet.
If finding and studying a distant star becomes not such an insoluble problem for modern science, then it is still quite difficult to detect a planet near this bright star, therefore, most often the found planets of other solar systems are large gas giants like our Jupiter and Saturn. Such planets outside our solar system are called exoplanets... Now it is already known about the existence of 884 planets that have their own Sun stars, and in the Milky Way galaxy itself, according to some data, there should be more than 100 billion planets, from 5 to 20 billion of which, possibly, have characteristics similar to our Earth.
Known planetary systems
PSR 1257 + 12 is the very first planetary system, a pulsar that transmits pulses of radio emission in the form of periodically repeating bursts, which were discovered in 1991 by the Polish astronomer Alexander Wolschan.
Pulsar PSR 1257 + 12 is located 1000 light-years from our solar system. Four planets have been discovered in a single system B, C and D that resemble our Mercury, Venus and Earth, as well as an unconfirmed fourth dwarf planet like our Pluto.
The planets, indeed, have similarities with the terrestrial planets of our system. Thus, the orbital of planet B around another Sun is 25.262 days; planet C - 66.5419 days; planet D - 98.2114 days. True, despite the fact that 2 of them are planets close in mass and some parameters to the Earth, living conditions for humans on the planets are unacceptable due to the strong microwave radiation of the pulsar, the strongest magnetic field, besides, the planets are likely to have constant acid rain ...
If at least some organic life can exist on planets, then only under the depth of protective ice and water. On the surface, the radiation doses are too strong for the development of organisms, but there is an opinion that the so-called bacterium Deinococcus radiodurans found on Earth can survive even higher doses of radiation, which means that there is a possibility that evolution on other planets is able to create organisms for life in conditions pulsar.
Upsilon Andromeda is a yellow star similar to our Sun in which a planetary system was discovered. This star lies 43.9 light years away and is visible to the naked eye. Four planets were discovered in its rays.
Planet B has an orbital period of only 4.617 days and bears a resemblance to our hot giant, Jupiter; planet C - the gas giant revolves around its star for 241.5 days; planet D - equal to 10 masses of Jupiter with a revolution of 1284 days, and the orbit of the fourth planet E, which is much farther than other planets of its system, has been calculated.
The star is a yellow dwarf star, visible to the naked eye in good sky, closely similar in parameters to the Sun in the constellation Pegasus at a distance of 50.1 light years.
The open planet b, according to the characteristics of an exoplanet, having an orbit around its Sun, is most likely a gas giant and has a short orbital period of 4.23 days
A Sun-like star in the constellation Cancer in the planetary system of which there is a Planet f on which theoretically there can be water.
In total, the system knows about 5 planets, but there are assumptions about the existence of 2 more planets. Planet e is interesting - a hot super-earth, the mass of which exceeds the mass of our Earth and has a large proportion of carbon in its composition, and the orbital period is 17 hours 41 minutes. The fifth planet discovered was planet f, which is 45 times more massive than Earth, but the surface temperature is slightly warmer than Earth's, because its star is dimmer and colder than our Sun. Water is assumed to be abundant on the surface of this fifth planet.
A very young, still emerging new solar system UX Taurus is located 450 light-years from our Sun. It was discovered using a spacecraft with a powerful infrared telescope Spitzer, which operates in orbit of planet Earth. A gas and dust disk with a huge gap was discovered around the star of this new solar system, and since this is not observed in other protoplanetary disks of young stars, astronomers agreed that we had an amazing picture of the formation of a new system from the Sun and the planets surrounding it.
Exoplanets of other solar systems
An exoplanet in the constellation Ophiuchus, located 40 light years from Earth, on which an ocean is theoretically possible. The planet is 2.5 times larger and 6.5 times heavier than the Earth, and a year lasts only 36 hours, according to some calculations and assumptions, the planet may consist of 75% water and 25% of rocky materials, and hydrogen must be present in the atmosphere and helium. A unique phenomenon of properties on the planet, due to the composition of the planet's atmosphere from thick water vapor at a high temperature of 200 ° C, researchers believe that water on the planet is in a state uncharacteristic for our Earth, such as "hot ice" and "super-liquid water".
The planet, discovered by the Kepler telescope of the same name, is the smallest of the exoplanets, judging by its density, it is an iron planet, has a mass 1.4 times that of the Earth and revolves around itself almost like our planet in 0.84 Earth days. True, the temperature of the planet's surface is most likely very hot, 1527 ° C.
Gliese 667 Cc
Gliese 667 C c is the second planet from the red dwarf star Gliese 581 in the constellation Libra, which is 20 light years away. The temperature of the atmosphere, similar to that of the Earth, on the planet's surface can be +27 ° C, given the presence of 1% CO2 in the composition with the greenhouse effect.
The mother star around which the planet revolves is not bright, because it is a red dwarf, but due to its close location it receives up to 90% of its energy (about the same the Earth receives from the Sun), which means that the conditions for the existence of life on this planet are quite are acceptable. Due to its proximity to its sun and the huge size of the star, the sky above the planet's surface will scatter a reddish color.
Gliese 581 d
The third planet from its red dwarf star Gliese 581, which may be suitable for life. This is a very large planet 2 times larger than our Earth. Interestingly, simulations of the planet for habitability have shown that it may have an atmosphere with very high clouds of dry ice, where precipitation is possible at lower altitudes.
The planet is located very close to the star, but since its sun is a red dwarf, it receives heat from its star not so hot and the temperature on the planet's surface is not much more than 0 ° C. In the daytime, a huge ball of star with a faint glow hangs over the planet, painting the landscape with a gloomy orange-red color.
Gliese 581 g
But on this planet located in the system of the red dwarf star Gliese 581 at a distance of 20 light years from us, the conditions are the most suitable for the existence and development of life of all exoplanets known at the moment. The planet, which is the fourth in a row from its red dwarf sun, may have an atmosphere and water in liquid form, and the surface consists of rocky mountains and rocky formations. There is an interesting assumption that the planet is always facing only one side of its star, which means that on one hot half of the planet it is always day, where the temperature rises to +71 ° C, and on the other it is eternal night, where theoretically there can be snow at a temperature −34 ° C. While the planet may have a dense atmosphere, the distribution of heat could warm the entire planet, making some areas quite habitable.
By the way, Australian scientist Ragbir Bhatal, who is a member of the SETI project for the search for extraterrestrial civilizations, claimed that in December 2008 he discovered sharp flares from the surface of the planet, resembling the action of a laser. Unfortunately, some scientists have refuted this version.
The closest exoplanet in size to our Earth, but due to its very close location to its sun, the surface temperature can be 760 ° C, and it can run very quickly a year - in just 6 days.
A planet falling into a habitable zone where conditions could theoretically become suitable for life. The planet is located in the constellation Parus at a distance of 36 light years from us and is warmed by the moderate rays of its warm orange dwarf star HD 85512. The temperature on the surface can be 25 ° C, but if the atmosphere is similar in properties to Earth, then due to its greenhouse effect the value will already be +78 ° C. The planet has a high probability of liquid water availability. The mother sun of this planet shines 8 times fainter than our Sun, painting the surface with a moderate orange color, but due to its proximity to the star, the planet receives the heat and light necessary for the emergence of organic life.
An ocean planet located about 620 light years from our Earth. The period of the planet's revolution around its star Kepler is 290 days, and the temperature, if it turns out that the planet has an atmosphere, will be about + 22 ° C, which is beneficial for life on it. The only thing is that this planet most likely belongs to the class of mini-neptunes, its entire surface most likely consists of the ocean, so if there is life on the planet, it is most likely aquatic.
GD 66 b
GD 66 b - probably a helium exoplanet orbiting the white dwarf GD 66. The planet most likely has very low temperatures and twilight reigns on it, which is associated with the low luminosity of its home sun - a white dwarf.
Planet with 3 suns in the constellation Cygnus. Exoplanet located in an amazing system of three stars. From the surface of this planet, you can see the main bright star HD 188753 A, which is a powerful source of light and heat, as well as the much less bright orange dwarf HD 188753 B and the dim red dwarf HD 188753 C. The planet belongs to the class of gas giants and has a revolution around its main star 3.35 days.
The closest planet to Earth in another solar system, Alpha Centauri, is approximately 4.37 light years from our Sun. It has its own solar type star Alpha Centauri B and is a super-earth type planet and orbits very close to its star at a distance of about 6 million km, so the surface temperature is very high 1200 ° C, and if you can imagine a view of the starry sky from this planet , then (the image by the artist in the picture) from the planet you can see a huge glowing native star and a small luminous point (in the upper right corner of the picture) - our Sun.
Planet Earth, solar system, and all the stars visible to the naked eye are in Milky Way Galaxy, which is a barred spiral galaxy with two pronounced arms starting at the ends of the bar.
This was confirmed in 2005 by the Lyman Spitzer Space Telescope, which showed that the central bar of our galaxy is larger than previously thought. Spiral galaxies with a bar - spiral galaxies with a bar (“bar”) of bright stars emerging from the center and crossing the galaxy in the middle.
Spiral branches in such galaxies start at the ends of the barriers, whereas in ordinary spiral galaxies they exit directly from the core. Observations show that about two-thirds of all spiral galaxies are barred. According to existing hypotheses, the bridges are centers of star formation that support the birth of stars in their centers. It is assumed that through orbital resonance, they let gas through them from the spiral arms. This mechanism provides an influx of building material for the birth of new stars. The Milky Way along with the Andromeda Galaxy (M31), the Triangle (M33), and more than 40 smaller satellite galaxies form the Local Group of Galaxies, which in turn is part of the Virgo Supercluster. "Using an infrared image from NASA's Spitzer telescope, scientists have discovered that the Milky Way's elegant spiral structure has only two dominant arms from the ends of the central bar of stars. Our galaxy was previously thought to have four major arms."
/s.dreamwidth.org/img/styles/nouveauoleanders/titles_background.png "target \u003d" _blank "\u003e http://s.dreamwidth.org/img/styles/nouveauoleanders/titles_background.png) 0% 50% no-repeat rgb (29, 41, 29); "\u003e Galaxy structureIn appearance, the galaxy resembles a disk (since most of the stars are in the form of a flat disk) with a diameter of about 30,000 parsecs (100,000 light years, 1 quintillion kilometers) with an estimated average disk thickness of about 1,000 light years, the diameter of the bulge is the center of the disk is 30,000 light years. The disk is immersed in a spherical halo, and a spherical crown is located around it. The center of the galactic nucleus is located in the constellation Sagittarius. The thickness of the galactic disk where it is solar system with planet Earth is 700 light years. The distance from the Sun to the center of the Galaxy is 8.5 kilo parsecs (2.62.1017 km, or 27,700 light years). solar system is located on the inner edge of the arm called the Orion arm. In the center of the Galaxy, apparently, there is a super massive black hole (Sagittarius A *) (about 4.3 million solar masses) around which, presumably, a black hole with an average mass of 1000 to 10,000 solar masses and an orbital period of about 100 years revolves and several thousand comparatively small ones. The galaxy contains, according to the lowest estimate, about 200 billion stars (current estimates range from 200 to 400 billion). As of January 2009, the mass of the Galaxy is estimated at 3.1012 solar masses, or 6.1042 kg. The bulk of the Galaxy is contained not in stars and interstellar gas, but in a non-luminous halo of dark matter.
Compared to the halo, the disk of the Galaxy rotates noticeably faster. Its rotation speed is not the same at different distances from the center. It rapidly increases from zero in the center to 200-240 km / s at a distance of 2 thousand light years from it, then decreases slightly, increases again to approximately the same value, and then remains almost constant. The study of the features of the rotation of the disk of the Galaxy made it possible to estimate its mass; it turned out that it is 150 billion times greater than the mass of the Sun. Age Milky Way Galaxy is equal13,200 million years old, almost as old as the universe. The Milky Way is part of the Local Group of Galaxies.
/s.dreamwidth.org/img/styles/nouveauoleanders/titles_background.png "target \u003d" _blank "\u003e http://s.dreamwidth.org/img/styles/nouveauoleanders/titles_background.png) 0% 50% no-repeat rgb (29, 41, 29); "\u003e Location of the Solar System solar system is located on the inner edge of the Orion arm, in the marginal part of the Local Supercluster, which is sometimes also called the Virgo Super Cluster. The thickness of the galactic disk (where it is solar system with the planet Earth), is 700 light years. The distance from the Sun to the center of the Galaxy is 8.5 kilo parsecs (2.62.1017 km, or 27,700 light years). The sun is located closer to the edge of the disk than to its center.
Together with other stars, the Sun revolves around the center of the Galaxy at a speed of 220-240 km / s, making one revolution in about 225-250 million years (which is one galactic year). Thus, for the entire time of its existence, the Earth has flown around the center of the Galaxy no more than 30 times. The galactic year of the Galaxy is 50 million years, the orbital period of the bar is 15-18 million years. In the vicinity of the Sun, it is possible to track sections of two spiral arms, which are approximately 3 thousand light years distant from us. According to the constellations where these areas are observed, they were named the Sagittarius arm and the Perseus arm. The sun is located almost midway between these spiral arms. But relatively close to us (by galactic standards), in the constellation Orion, there is another, not very clearly defined arm - the Orion arm, which is considered an offshoot of one of the main spiral arms of the Galaxy. The speed of rotation of the Sun around the center of the Galaxy almost coincides with the speed of the compaction wave that forms the spiral arm. This situation is atypical for the Galaxy as a whole: the spiral arms rotate at a constant angular velocity, like spokes in wheels, and the movement of stars occurs with a different pattern, therefore, almost the entire stellar population of the disk either gets inside the spiral arms or falls out of them. The only place where the speeds of stars and spiral arms coincide is the so-called corotation circle, and it is on this circle that the Sun is located. For the Earth, this circumstance is extremely important, since violent processes occur in the spiral arms, forming powerful radiation, destructive for all living things. And no atmosphere could protect against him. But our planet exists in a relatively quiet place in the Galaxy and has not been exposed to these cosmic cataclysms for hundreds of millions (or even billions) years. Perhaps this is why life on Earth was able to be born and survive, the age of which is 4.6 billion years. Diagram of the location of the Earth in the universe in a series of eight maps, which show, from left to right, starting with the Earth, moving in Solar system, to neighboring star systems, to the Milky Way, to local Galactic groups, tolocal Virgo superclusters, on our local super-cluster, and ends up in the observable universe.
Solar system: 0.001 light years
Neighbors in interstellar space
Milky Way: 100,000 light years
Local Galactic Groups
Local Super Cluster Virgo
Local over the galaxy cluster
Observable Universe
For those who want to arrange a space adventure for their son for his birthday, http://prazdnik-servis.ru/ will always come to the rescue. They will turn any holiday into a fairy tale.The universe is full of unexplained mysteries. In it, for example, there are hypervelocity stars, which, incidentally, do not emit light, and clouds of dust that taste like raspberries and smell like rum. There are phenomena in the universe, the understanding of which is clearly outside the scope of our world (a pun intended here). There are also mysterious planets outside our solar system. These planets, which are outside our solar system, were discovered in the last decade of this century, after Alexander Volschan discovered the first three in 1994. Let's take a closer look at ten of the most mystical of them.
10. Planet Osiris (HD 209458 b)
HD 209458 b is located 150 light-years from planet Earth in the constellation Pegasus, and is the first exoplanet to be discovered when the planet passes through the disk of a star. It is 30% larger than Jupiter, and its orbit is 1/8 of the distance between Mercury and the Sun. Naturally, the temperature on the planet is very high: about 1000 Celsius. It is a gas planet that, under the influence of incredible heat and tremendous pressure, collides with the evaporation of various gases, which leads to the loss of its gravitational field, including the loss of hydrogen, oxygen and carbon. Surprised scientists have created a completely new classification for this planet and called it chthonic.
9. Stone showers (CoRoT-7b)
CoRoT-7b is a strange and mysterious planet outside the solar system, and the first rocky planet discovered outside our solar orbit. It is assumed that it was originally a giant gas giant, like Jupiter or Saturn, but due to its proximity to the star, it gradually lost all layers of its atmosphere.
Since the planet is always facing the star with only one side, the temperature on the illuminated side reaches 2204 Celsius, while on the dark side the temperature is 176 Celsius. These conditions lead to precipitation from solid rock: evaporating stones fall out in the form of liquid stone rain and freeze on the surface.
8. Planet Methuselah (PSR 1620-26 b)
PSR 1620-26 b is probably the oldest planet in the universe and is old enough to be the prototype for many astrophysical phenomena. It is three times older than the Earth and is considered only a billion years younger than the Universe itself, although it is traditionally believed that the planets cannot be the same age as the Universe, since at the time of the Big Bang there were no favorable conditions and necessary materials for the formation of planets. Methuselah revolves around a double star: a white dwarf and a pulsar, located in a cluster of stars in the constellation Scorpio.
7. Planet from Hell (Gliese 581c)
Gliese 581c is the most suitable for subsequent colonization, except that the conditions on it are truly hellish. It is always turned with one side to the red dwarf, around which it revolves, and the temperature difference on the light and dark sides is such that if you are standing on one side, you will immediately evaporate, but as soon as you take a step to the other side, you will immediately freeze ... In the narrow, more or less livable band between these two extremes, there are other problems. The sky of this planet is hellish red, since the planet is at the very bottom of the visible light spectrum, so if there are photosynthetic plants on the planet, then because of this they are all black.
6. Planet - black hole (TrES-2b)
TrES-2b is very similar to Jupiter: they are both almost the same size and it orbits a sun-like star - only it is 760 light-years away. This Jupiter-class gas giant reflects about 1% of the light incident on it. In other words, it absorbs the light falling on it so strongly that it is considered the darkest planet. It is darker than the blackest acrylic paint or charcoal. The atmosphere is believed to contain specific chemicals or compounds. Interestingly, at an atmospheric temperature of 982 Celsius, the planet is hot enough to emit a faint, reddish glow, which is most likely visible because it completely absorbs all other light.
HD 106906 b is the “eternally lonely guy” because it hangs around the back of the Southern Cross constellation, orbiting its star at a distance of 60,000,000,000 kilometers, which is 20 times the distance between Neptune and the Sun. Located almost 300 light-years from Earth, this super-Jupiter-class planet, which is 11 times larger than Jupiter itself, is so far from its star that it simply cannot form enough solid material necessary for its complete formation. Astrophysicists speculate that it is an under-formed star, thus questioning the binary system as it is too small for binary formations.
4. Swollen gas planet (Hat P 1 Hat p 1 o kepler est operando)
HAT-P-1 is a very mysterious planet outside the solar system, located 450 light years away. It was recently discovered by the Harvard-Smithsonian Center for Astrophysics. It is a giant gas planet about half the size of Jupiter, but the startling fact is that, despite its size, it is so small that its mass is comparable to that of a plug. It is classified as "hot Jupiter", although 25% more than the acceptable model for this classification, which scares astrophysicists who are trying to figure out why it is so "swollen". Scientists suspect that she can swim in water, and it is curious to check how true this fact is.
3. A planet with an incredible number of rings (J1407 b)
J1407 b was discovered in 2012 and has been recently processed and submitted. It is located 400 light-years from Earth. The most striking fact about this planet is that it has a ring system like Saturn, but these rings are 200 times larger than those around Saturn. The rings are so large that if they belong to Saturn, they would dominate the Earth's sky, larger than the Moon, and scientists would also observe a 56-day Solar Eclipse. The gaps between the rings are thought to represent orbiting exo-moons around this exoplanet.
2. Planet of blazing ice (Gliese 436 b)
Gliese 436 b is another planet from the Gliese system. It is 20 times the size of Earth, about the size of Neptune. The planet is 6.9 million kilometers from its star, compared to Earth, which is 150 million kilometers from the Sun. The planet's temperature is 438 Celsius, and its surface is covered with burning ice. The planet's immense gravitational force holds the water molecules too tightly together to evaporate, so they do not leave the planet. Hot ice is called ice-ten, after the substance from Kurt Vonnegut's novel Cat's Cradle.
1. Diamond planet (55 Cancer e)
Discovered in 2014, 55 Cancer e is twice the size of Earth and 8 times its mass. This planet is also called "super-Earth". In addition to graphite and other silicates, the planet mainly includes diamond. Once a star from a binary system began to "eat" this planet, leaving in the end only a stone core. Its temperature is around 2148 degrees Celsius. The subsurface value of the diamond planet is $ 26.9 nonillion (1,054), which is 384 quintillion (1,018) times the GDP of the Earth, which is $ 74 trillion. Extraction of just 0.187% of its subsoil would cover the external debt of all governments on Earth, amounting to $ 50 trillion. All they had to do was cover a distance of 40 light years.
There are about 200 exoplanets already discovered in the Universe. The often striking characteristics of these mysterious and wondrous planets outside the solar system are completely confusing to the entire world of science, especially when the scientific facts about these exoplanets sound much more unusual than the stories from science fiction.
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The total number of exoplanets in the Milky Way galaxy is over 100 billion. An exoplanet is a planet that lies outside our solar system. Currently, scientists have discovered only a small fraction of them. About the 10 most incredible planets in this post.
The darkest exoplanet is the distant Jupiter-sized gas giant TrES-2b.
Measurements have shown that the planet TrES-2b reflects less than one percent of the light, making it blacker than coal and naturally darker than any of the planets in the solar system. The work on this planet was published in the Monthly Notices journal of the Royal Astronomical Society. Planet TrES-2b reflects less light even than black acrylic paint, so this is a truly dark world.
TrES-4
The largest planet found in the universe is TrES-4. It was discovered in 2006, and it is located in the constellation Hercules. A planet called TrES-4 orbits a star about 1400 light-years from planet Earth.
Researchers claim that the diameter of the discovered planet is almost 2 times (more precisely 1.7) larger than the diameter of Jupiter (this is the largest planet in the solar system). TrES-4 temperature is about 1260 degrees Celsius.
COROT-7b
A year on COROT-7b lasts a little over 20 hours. It is not surprising that the weather in this world is, to put it mildly, exotic.
Astronomers have suggested that the planet is made of molten and solid rock, and not of frozen gases, which will certainly boil away under such conditions. The temperature, according to scientists, drops from +2000 C on an illuminated surface to -200 C at night.
WASP-12b
Astronomers saw a cosmic cataclysm: a star engulfs its own planet, which is in close proximity to it. We are talking about the exoplanet WASP-12b. It was discovered in 2008.
WASP-12b, like most of the known exoplanets discovered by astronomers, is a large gaseous world. However, unlike most other exoplanets, WASP-12b orbits its star at a very close distance - just over 1.5 million kilometers (75 times closer than Earth from the Sun).
The vast world of WASP-12b has already looked into the face of its death, researchers say. The planet's biggest problem is its size. It has grown to such an extent that it cannot hold its matter against the gravitational forces of its native star. WASP-12b gives off its matter to the star at a tremendous rate: six billion tons every second. In this case, the planet will be completely destroyed by a star in about ten million years. By cosmic standards, this is very little.
Kepler-10b
With the help of a space telescope, astronomers were able to detect the smallest rocky exoplanet, which is about 1.4 times the diameter of Earth.
The new planet was designated Kepler-10b. The star it revolves around is about 560 light-years from Earth in the constellation Draco and is similar to our Sun. Belonging to the "super-earth" class, Kepler-10b is in an orbit quite close to its star, orbiting around it in just 0.84 Earth days, while the temperature on it reaches several thousand degrees Celsius. According to scientists, with a diameter of 1.4 Earth's diameter, Kepler-10b has a mass of 4.5 Earths.
HD 189733b
HD 189733b is a Jupiter-sized planet orbiting its star 63 light-years away. Although this planet is about the size of Jupiter, its proximity to its star makes it significantly hotter than the dominant gas giant in our solar system. As with other found hot Jupiters, the rotation of this planet is synchronized with its orbital motion - the planet is always turned to the star on one side. The orbital period is 2.2 Earth days.
Kepler-16b
Analysis of the data on the Kepler-16 system showed that the exoplanet Kepler-16b discovered in it in June 2011 revolves around two stars at once. If the observer could be on the surface of the planet, he would see how two suns rise and set, just like on the planet Tatooine from the fantastic saga "Star Wars".
In June 2011, scientists announced that there was a planet in the system, which was designated Kepler-16b. After further detailed research, they found that Kepler-16b revolves around the binary star system in an orbit roughly equal to that of Venus, and makes one revolution in 229 days.
Thanks to the joint efforts of amateur astronomers who participated in the Planet Hunters project and professional astronomers, it was possible to find a planet in a system of four stars. The planet revolves around two stars, around which, in turn, two more stars revolve.
PSR 1257 b and PSR 1257 c
2 planets revolve around a dying star.
Kepler-36b and Kepler-36c
Exoplanets Kepler-36b and Kepler-36c - These new planets were discovered by the Kepler telescope. These unusual exoplanets are strikingly close to each other.
Astronomers have discovered a pair of neighboring ekplanets with different densities in orbits very close to each other. Exoplanets are too close to their star and are not in the so-called "habitable zone" of the star system, that is, a zone where liquid water can exist on the surface, but that is not what they are interested in. Astronomers were surprised by the very close proximity of these two completely different planets: the orbits of the planets are as close as no other orbits of the previously discovered planets.
