Place the Solar system in our Galaxy

Planet Earth, the Solar system . and all the stars visible to the naked eye are in the milky Way Galaxy . which is a spiral galaxy with a jumper with two distinct sleeves starting at the ends of the jumper.

This was confirmed in 2005 a space telescope named the Lyman Spitzer, which showed that the centre bar of our galaxy is larger than previously thought. Spiral galaxy barred spiral galaxy barred (“bar”) of bright stars emerging from the center and crossing the galaxy in the middle. Spiral branches in these galaxies begin at the ends of the crosspieces, whereas in normal spiral galaxies, they come directly from the kernel. Observations show that about two thirds of all spiral galaxies have a bar. According to existing hypotheses, the jumpers are centers of star formation, supporting the birth of stars in their centers. It is expected that through orbital resonance, they are passed through a gas of spiral branches. This mechanism provides a flow of building material for the birth of new stars. Milky Way along with the Andromeda galaxy (M31),Triangle (M33), and more than 40 smaller galaxies-satellites, form the Local Group of Galaxies, which, in turn, is part of the Virgo Supercluster. “Using infrared images from NASA Spitzer telescope allowed scientists to discover that the elegant spiral structure of the milky Way has only two prevailing sleeves from the ends of the Central bar of stars. Previously it was thought that our galaxy has four main hoses “.

The Structure Of The Galaxy

In appearance, the galaxy resembles a disk (because the bulk is in the form of a flat disc) with a diameter of some 30,000 parsecs (100,000 light years, 1 trillion kilometers) at an estimated average thickness of the disk is about 1000 light years, the diameter of the bulge in the disk center is 30,000 light-years. The disk is immersed in a halo of spherical shape, and around it there is a spherical crown. The Central core of the Galaxy is in the constellation of Sagittarius. The thickness of the galactic disk in the place where the Solar system with the planet Earth is 700 light years. The distance from the Sun to the galactic center of 8.5 kilo parsec (2,62•1017 km, or 27 700 light years). The solar system is located on the inner side of the sleeve called the sleeve of Orion. In the center of the Galaxy, apparently, is a super massive black hole (Sagittarius A*) (about 4.3 million Solar masses) around which, presumably, the rotation of the black hole of average weight from 1,000 to 10,000 Solar masses and a orbital period of about 100 years and several thousand relatively small. Galaxy contains, at the lowest estimate, about 200 billion stars (current rating ranges of assumptions from 200 to 400 billion). As of January 2009, the mass of a Galaxy is estimated to be 3•1012 Solar masses, or 6•1042 kg. Main mass of Galaxies is not in stars and interstellar gas, but not in a luminous halo of dark matter.

Compared to the halo disk of the Galaxy rotates significantly faster. The rotation speed is not the same at different distances from the center. It rapidly increases from zero at the center up to 200-240 km / s at a distance 2 thousand light years from him, then decreases slightly, then increases again to approximately the same value and then remains almost constant. Study of features of rotation of the disk of the Galaxy allowed us to estimate its mass, she was found to be 150 billion times the mass of the Sun. The age of the milky Way Galaxy is $ 13 200 million years, almost as old as the universe. The milky Way is part of the Local group of galaxies.

The location of the Solar system

The solar system is located on the inner side of the sleeve called the sleeve of Orion, in the peripheral parts of the Local Super clusters (Local Supercluster), which is sometimes also called Beyond the Virgo cluster.. The thickness of the galactic disk( in the place where the Solar system with the planet Earth) is 700 light-years. The distance from the Sun to the galactic center of 8.5 kilo parsec (2,62•1017 km, or 27 700 light years). The sun is closer to the edge of the disk than toward its center.

Together with other stars the Sun revolves around the Galaxy at a speed of 220-240 km / s, making one revolution in about 225-250 million years( one galactic year). Thus, for all time of existence of the Earth flew around the Galaxy center on not more than 30 times. Galaxy year Galaxy is 50 million years, the orbital Period of the bridges 15 to 18 million years. In the vicinity of the Sun possible to keep track of the plots of two spiral arms, which are far from us about 3 thousand light years. Through the constellations, which are characterized by these sections, they were given the name Sagittarius a sleeve and the sleeve of Perseus. The sun is almost in the middle between the spiral branches. But relatively close to us (by galactic standards), in the constellation Orion, is another one, not very clear sleeve — a sleeve of Orion, which is considered an offshoot of one of the major spiral arms of the Galaxy. The speed of rotation of the Sun around the galactic center almost coincides with the wave velocity of the seal, forming a spiral sleeve. Such situation is atypical for Galaxies in General: spiral arms rotate with a constant angular velocity, as spokes in the wheels, and the movement of stars takes place with a different pattern, so almost all of the stellar population of the disk that is inside the spiral arms, then drop out of them. The only place where the speeds of stars and spiral arms coincide — the so-called corotational circle, and it is the Sun. For the Earth this circumstance is extremely important because in spiral sleeves of the turbulent processes occur, forming a powerful radiation, harmful to all living things. And no atmosphere would not be able to protect. But our planet exists in a relatively quiet spot of the Galaxy, and for hundreds of millions (or even billions) of years have not been exposed to these cosmic cataclysms. Maybe that’s why on the Earth could be born and survive life, which stands at 4.6 billion years. The scheme of location of the Earth in the Universe in a series of eight cards. which show, from left to right, starting with the Earth moving in the Solar system . on a nearby star system, milky Way, local Galactic group, local super clusters of Virgo . at our local super clusters, and ends in the observable Universe.

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