What is a star, each of us knows from childhood.This is a heavenly body, which we see as a small luminous point in the night sky. In fact, all the stars are huge balls consisting of hot gases. They include ninety percent of hydrogen, slightly less than ten percent of helium, and in the rest - various impurities. In the center of the ball, the temperature is about six million degrees. This value corresponds to the limit that allows a free flow of a thermonuclear reaction. During this chemical process, hydrogen is converted to helium. As a result, a huge amount of thermal energy is released, which is transmitted into outer space in the form of bright light.
What is a star? It's the same as the sun. At the same time, small stars are ten times smaller in size than our luminary, and larger ones exceed its parameters one hundred and fifty times.
Often in response to a question about what a star is,astronomers call these fireballs the main bodies in the universe. The thing is that it is in them that the main volume of luminous matter that can be met in outer space is contained.
Stars in the sky, which we can observe ina telescope, are often surrounded by nebulae of various shapes. These tumors, which are clouds of gas and dust, can begin the process of compaction at any time. In this case, they will shrink into a figure in the form of a ball and warm up to a considerable temperature. When the thermal regime reaches six million degrees, thermonuclear interaction begins, that is, a new celestial body is formed.
Scientists have different types of stars. They are divided by their mass and glow. It is possible to divide the stages of the evolutionary process.
A class that contains stars in which the radiated energy is balanced with the energy of thermonuclear reactions, subdivides them according to the form of the luminescence into:
- white;
- blue;
- white and blue;
- yellow;
- white and yellow;
- Red;
- Orange.
The maximum temperature is observed in stars,having a blue glow, the minimum - in red. Our Sun belongs to the yellow form of the stars. His age exceeds four and a half billion years. The core temperature, which scientists calculated, is 13.5 million K, and the crowns - 1.5 million K.
What is a giant star?This type of light includes fire bodies that have a mass and diameters that exceed the Sun by several tens of thousands of times. Giants, issuing a red glow, are at a certain evolutionary stage. The diameter of the star increases by the time when hydrogen completely burns out in its core. At the same time, the temperature of combustion of gases decreases and the red glow spreads over millions of kilometers. To the giant stars include VV Cepheus A, VY of the Great Dog, KW Sagittarius and many others.
There are among the heavenly bodies and dwarfs. Their diameter is much smaller than the size of our Sun. There are dwarfs:
- white (cooling);
- yellow (similar to the Sun);
- Brown (often considered as planets);
- red (relatively cold);
- black (finally cooled and lifeless).
There is also a kind of variable stars. These luminaries are bodies that, at least once in the history of observation, have changed their brilliance and dynamics of development. They include:
- rotating;
- pulsating;
- eruptive;
- other unstable, new, as well as difficult to predict luminaries.
Such stars, which are represented mainly by bright blue and hypernovae, are very specific and have been little studied. Each of them is the result of the resistance of matter and the work of the forces of gravity.
To the stars also include black holes.It is believed that this is one of the steps in the evolutionary process of celestial bodies. Glow does not radiate such a body, but certain of its characteristics put it on a par with the stars.
