Galactic research Galaxies are giant star systems scattered across the endless distances of the universe. In the past, astronomers knew little about galaxies. Distant foggy objects attracted increased attention only after the invention of the telescope. Gradually more than 100 such objects were discovered, and already in the XVIII century, the first catalog of nebulae was made (nebulae - cosmic clusters of gas and dust, can be prolonged in several thousand light-years. Many nebulae are remnants of exploded stars or supernovae). Among them are some of the most beautiful creatures of nature, the cosmic "wonders of light" - spiral galaxies, which can be embodied in the nebula in the constellation of Andromeda.
Our galaxy also has a spiral shape. Other (non-continental) galaxies, visible without visual aids, but only in the Southern Hemisphere. Elliptic galaxies are quite common. Of extreme research, interest is those galaxies that are connected by bridges. There are also small dwarf galaxies. The stars we see in the night sky are the closest to our solar system. And a bright strip, visible on a dark, clear night, called the Milky Way.
- The Milky Way Our galaxy is a 120, 000 light-years flat disc with a convex center.
The stars on the disk are spiraled (only in the middle of this century did it become clear that the Milky Way is a giant sleeve twisted into a spiral of a huge star system). The number of its stars exceeds 100 billion (the exact number has not been established yet). Where new stars were born or are born, the turns of this huge spiral contain dust and gas. The galaxy"s disk rotates in its entirety, like a plate. The angular rotation speed around the center of the individual stars is different. Our Sun is 30, 000 light-years away from the center of the Milky Way, in the part of the helix called the Orion branch. Studying the relative motion of the stars, it has been established that the Sun also moves around the center of the galaxy in an orbit close to a circular one, at a speed of 220 km/sec. Modern measurements bring this value up to 250 km/sec.
Our galaxy (like others) is extremely similar to a living organism. It has a kind of metabolism - "space metabolism". Various objects and components of the galaxy"s hierarchy are in a state of continuous interaction. Our galaxy, according to most scientists, belongs to relatively young galaxies.
- Blackhole Scientists have recently discovered that a giant black hole may be in the middle of our galaxy.
Black holes are invisible space objects of very high density, formed after the explosion of large stars. They have such high gravity that even a ray of light cannot overcome. However, a black hole can be recognized by the X-ray rays emitted by the matter it sucks in. If we see stars revolving around a powerful but invisible source of X-rays, we can talk about the presence of a black hole.
Galaxy clusters More recently, scientists have believed that galaxies form a fairly homogeneous mass in the universe, evenly and monotonously distributed in the vast outer space. Everything turned out to be wrong! It turned out that the galaxies are actually lumped together, and between them, there are gaping emptinesses.
Thus, the large-scale structure of the universe was discovered, one of the most significant achievements of theoretical cosmology, observational astronomy, and practical astrophysics at the end of the 20th century. The largest of the clusters detected is more than 1 billion light-years long. The space cavities are equally long. Thus, the measured distances between the fibers reach 300 million light-years. Intensive study of galaxies, including with the help of radio telescopes, the discovery of background radiation, new space objects such as quasars, emitting tens of times more energy than the most powerful galaxies, has led to the emergence of new mysteries in the study of the universe.