What is a star?
Looking at the night sky, we see a lot of shiningstars. All children think that the asterisks are small and even fit in the palm, but adults know that it is not. But can everyone give a scientific definition?
Let's see what a star is from the point of view of astronomy.
Star in astronomy
A star in this area means a luminousthe heavenly body, which is visible in a cloudless night. Since the stars are distant from the Earth by several thousand kilometers, we see the stars only as luminous dots in the sky. Speaking scientifically, the star is a large gas ball that emits light and is suspended in a suspended state by its own gravity, as well as by the pressure produced by the reactions of thermonuclear fusion.
The star consists mainly of hydrogen-heliumelements. All the stars have the shape of a ball, which is possible thanks to gravity, which under pressure does not allow particles to scatter in different directions. Find out more about the composition of the star from the article What the stars consist of.
Why do we need stars?
From the standpoint of astronomy, stars havean important role. For example, the closest star to the Earth - the Sun - engenders life on Earth, filling it with the necessary energy. Also the sun gives us the warmth that gives birth to life. In addition, by heating and evaporating water, the Sun participates in the formation of clouds, which then fall out as precipitation.
The cluster of stars emits light. You can read about this in the article Why stars shine.
Types of stars
Stars can be divided into categories on several grounds:
- Color: blue, white-blue, white, yellow, yellow-white, orange, red.
- Shine changes: new, supernovas, hyperlinks, LBV (bright blue variables); ULX (ultra-bright X-ray sources). Distinguish the data of the star by the speed of the color change.
- By composition and temperature.
Learn about the differences between stars and planets in the article What are the differences of stars from the planets.
Other meanings of this word
The word "star" is also called:
- Famous and outstanding people in the regionart, science or sport: "Elena Isinbayeva - a star in pole vaulting". And in a figurative sense, the star is an unremarkable and ordinary person: "The local star has gone".
- A geometric figure based on triangular ledges along the circumference, as well as an object of this form: a star-shaped candle.
- Officer's insignia on epaulettes, as well as the Order of the Order (Order of the Red Star).
- Marine animal. More often you can find the phrase "starfish", which means an invertebrate animal of the echinoderms class.
These are the values that the word "star" can take. Other meanings of the words can be found in the Definitions section.
