Many facts known today seem so familiar and commonplace that it is difficult to imagine how you ever lived without them.However, scientific truth for the most part did not occur at the dawn of humanity.In many ways it concerns knowledge about outer space.Types of nebulae, galaxies, stars are now known to almost everyone.Meanwhile the way for the modern understanding of the universe has been long enough.People did not immediately realize that the planet is - a part of the solar system, and it - the Galaxy.Types of galaxies in astronomy began to be studied even later, when it is understood that the Milky Way is not alone and it is not limited to the universe.The founder of the classification, as well as general knowledge of the cosmos is "milk road" became Edwin Hubble.Through his research today, we are very much aware of the galaxies.
Types of galaxies in the universe
Nebula Hubble studied and proved that many of them are formations similar to the Milky Way.On the basis of the collected material he described what kind of a galaxy and what types of such space objects exist.Hubble measured the distance to some of them and offered his classification.She scientists use today.
All the many systems in the universe he divided into 3 types: elliptical galaxies, spiral and irregular.Each type is actively studied by astronomers around the world.
piece of the universe, where the Earth, the Milky Way, is a type of "spiral galaxies."Types of galaxies are allocated on the basis of differences in their forms, affecting certain properties of the objects.
Spiral
Types of galaxies spread throughout the universe is not the same.According to current data are more likely to meet spiraling.In addition to the Milky Way refers to this type of Andromeda (M31) and galaxy in the constellation Triangulum (M33).Such objects are easily recognizable structure.If you look from the outside, it looks like this galaxy top view will remind divergent concentric circles on the water.From the center of the spherical thickening, called bulge diverge spiral arms.The number of branches is different - from 2 to 10. The entire disk with spiral arms is within the rarefied clouds of stars, which astronomers call the "halo".The core of the galaxy is a cluster of stars.
subtypes
in astronomy to describe spiral galaxies used the letter S. They are divided into types depending on structured sleeves and features the general form:
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galaxy Sa: sleeve tightly wound, smooth and unformed, the bright bulge and extended;
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galaxy Sb: Sleeves powerful, clear and bulge less pronounced;
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galaxy Sc: Sleeves are well developed, are ragged structure, visible bulge bad.
In addition, some systems have a central spiral practically straight jumper (it is called "bar").The designation of the galaxy in this case, added the letter B (Sba or Sbc).
Formation
formation of spiral galaxies, apparently, similar to the appearance of the waves from a stone on the water surface.By the appearance of arms, according to scientists, he has led a push.Sami spiral branches are waves of high density material.Nature push may vary, one option - to move the mass of the central star.
Spiral branches - a young star and neutral gas (the main element - hydrogen).They lie in the plane of rotation of the galaxy, because it resembles a flattened disk.The formation of young stars and maybe in the middle of such systems.
nearest neighbor
Andromeda - a spiral galaxy: a top view on it reveals several branches emanating from a common center.From the Earth to the naked eye and can be seen as diffuse nebulae.For its size of our galaxy neighbor, slightly higher than its 130 thousand light-years in diameter.
though Andromeda is the closest galaxy to the Milky Way, and the distance to it is huge.Light to overcome it, it takes two million years.This fact perfectly explains why missions to our neighboring galaxy is only possible in science fiction books and movies.
Elliptic systems
Let us now consider other types of galaxies.Photo elliptic system well demonstrates its difference from spiraling brother.In a galaxy not have sleeves.She looks like an ellipse.Such systems can be compressed to varying degrees, represent a kind of lens or ball.In these galaxies hardly meets the cold gas.The most impressive representatives of this type are filled with rarefied hot gas, whose temperature reaches a million degrees and higher.
hallmark of many elliptical galaxies - a reddish tint.For a long time astronomers have thought it a sign of the antiquity of these systems.It was believed that they consist mainly of old stars.However, studies in recent decades have shown the fallacy of this assumption.
Education
was common for a long time is another hypothesis related to elliptical galaxies.They were considered the first of any, formed shortly after the Big Bang.Today, this theory is considered outdated.A large contribution to its rebuttal made by German astronomers Alar and Yuri STP, and American scientist Francois Schweizer.Their research and discoveries of recent years confirm the validity of the other hypotheses, hierarchical model of development.According to her larger structures formed from a sufficiently small, that is, galaxies were formed not at once.Their appearance was preceded by the formation of star clusters.
Elliptic systems on modern representations formed from the merger of the spiral arms.One evidence of this - a large number of "twisted" the galaxies observed in remote areas of space.On the contrary, in most areas close significantly higher concentration of elliptic systems, quite bright and extended.
Symbols
Elliptical galaxies in astronomy and received his designation.For them, they use the symbol "E" and the numbers from 0 to 6, which indicates the degree of flattening of the system.E0 - galaxy is practically correct spherical form, and the E6 - very flat.
surging core
elliptical galaxies are NGC 5128 system in the constellation Centaurus and M87, located in Virgo.Their feature is the powerful radio emission.Astronomers are interested primarily in the central part of the device of such galaxies.Observations of Russian scientists and research Hubble Space Telescope show a sufficiently high activity of this area.In 1999, American astronomers received data about the kernel elliptical galaxy NGC 5128 (the constellation Centaurus).There's a constant movement are huge masses of hot gas around the center of the swirl, possibly a black hole.Precise data on the nature of such processes yet.
Systems irregularly shaped
Appearance galaxy third type is not structured.Such systems are ragged objects chaotic form.Irregular galaxies are found in the vast space of other less common, but their study contributes to a more accurate understanding of the universe occurring processes.Up to 50% of the mass of such systems is gas.In astronomy, usually denoted by the symbol of a galaxy like Ir.
satellites
to galaxies of irregular shape are two of the most closely located to the Milky Way.It's his companions: the Large and Small Magellanic Cloud.They are clearly visible in the night sky of the southern hemisphere.Most of the galaxies located at a distance of 200 000 light-years away, and less separated from the Milky Way - 170000 St.years.
astronomers scrutinize expanses of these systems.And the Magellanic Clouds fully repay for it: in the satellite galaxies are often found very interesting objects.For example, Feb. 23, 1987 in the Large Magellanic Cloud broke supernova.Of particular interest is the emission and Tarantula Nebula.It is located in the Large Magellanic Cloud.Here scientists have found a permanent region of star formation.Some luminaries constituting the nebula, only two million years.In addition, here it is the most impressive of the detected stars in 2011 - RMC 136a1.Its weight is 256 solar.
interaction
main types of galaxies form and describe the characteristics of the elements of space systems.But equally interesting is the question of their interaction.It's no secret that all space objects are in constant motion.No exception and galaxies.Types of galaxies, at least some of their representatives may have formed during the fusion or collision between the two systems.
If we remember that represent such objects, it becomes clear how major changes occur during their interactions.The collision released a huge amount of energy.It is interesting that such events are even more likely to occur in the vastness of space, than a meeting of two stars.
However, not all "communication" of galaxies end collisions and explosions.A small system can go through their larger brethren, thus disturbing its structure.Thus formed the formation of similar appearance with elongated corridors.They are composed of stars and gas, and are often the areas of formation of new stars.Examples of such systems are well known to scientists.One of them - Cartwheel galaxy in the constellation Sculptor.
In some cases, the system does not collide, and pass each other, or only slightly touch.However, regardless of the degree of interaction it leads to serious structural changes in both galaxies.
future
According to scientists it is possible that after a fairly long time the Milky Way devour its next satellite, recently discovered by a tiny space standards system, located 50 light-years away.These studies have shown impressive longevity of this satellite, which is likely to end in the process of merging with its larger neighbor.
Collision - a possible future for the Milky Way and Andromeda.Now huge neighbor separates from us about 2.9 million light years.The two galaxies approach each other at a speed of 300 km / s.The probability of collision of the scientists happen after three billion years.However, whether it will happen or only slightly galaxy will touch each other today, no one knows.To predict is not enough data about the features of the motion of both objects.
Modern astronomy detailed studies cosmic structures such as galaxies: the types of galaxies, especially the interaction of their differences and similarities, the future.This area has a lot of unknown and requires further study.Species structure of galaxies known, but there is no precise understanding of many parts, such as those associated with their formation.Modern pace of improvement of knowledge and technology, however, give hope for significant breakthroughs in the future.In any case, the galaxy will not cease to be the focus of many studies.And this is connected not only with curiosity, inherent in all people.The data on cosmic laws of life and star systems make it possible to predict the future of our piece of the universe, the Milky Way galaxy.
