Astronomy is the science that studies celestial objects. Considers stars, comets, planets, galaxies, and also does not disregard existing phenomena occurring outside the Earth's atmosphere, such as cosmic radiation.
Studying astronomy, you can get an answer to the question “Heavenly bodies that glow themselves. What is this?”.
Solar system bodies
To find out if there are celestial bodies that glow themselves, you first need to understand what celestial bodies the solar system consists of.
The solar system is a planetary system, in the center of which is a star - the Sun, and around it are 8 planets: Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune. In order for a celestial body to be called a planet, it must meet the following requirements:
- Make rotational movements around the star.
- Be shaped like a sphere, due to sufficient gravity.
- Do not have other large bodies around its orbit.
- Don't be a star.
Planets do not emit light,they can only reflect the rays of the sun falling on them. Therefore, it cannot be said that the planets are celestial bodies that glow on their own. These celestial bodies include stars.
The sun is the source of light on Earth
The celestial bodies that glow by themselves are the stars. The closest star to Earth is the Sun. Thanks to its light and warmth, all living things can exist and develop. The sun is the center around which the planets, their satellites, asteroids, comets, meteorites and cosmic dust revolve.
The sun appears to be a solid spherical object, because when you look at it, its contours look quite distinct. However, it does not have a solid structure and consists of gases, the main among which is hydrogen, and other elements are also present.
To see that the Sun does not have clear contours, you need to look at it during an eclipse. Then you can see that it is surrounded by a driving atmosphere, which is several times larger than its diameter. With normal glare, this halo is not visible because of the bright light. Thus, the Sun has no exact boundaries and is in a gaseous state.
Stars
The number of existing stars is unknown, they are located at a great distance from the Earth and are visible as small dots. Stars are celestial bodies that glow on their own. What does this mean?
Stars are hot balls of gas in which thermonuclear reactions take place. Their surfaces have different temperatures and densities. The size of the star is alsodiffer from each other, while they are larger and more massive than the planets. There are stars larger than the Sun, and vice versa.
A star consists of gas, mostly hydrogen. On its surface, from high temperature, the hydrogen molecule breaks up into two atoms. An atom is made up of a proton and an electron. However, under the influence of high temperatures, atoms "release" their electrons, resulting in a gas called plasma. An atom left without an electron is called a nucleus.
How stars emit light
A star, due to the gravitational force, tries to compress itself, as a result of which the temperature rises strongly in its central part. Nuclear reactions begin to occur, as a result, helium is formed with a new nucleus, which consists of two protons and two neutrons. As a result of the formation of a new nucleus, a large amount of energy is released. Particles-photons are released as an excess of energy - they also carry light. This light exerts a strong pressure that emanates from the center of the star, resulting in a balance between the pressure emanating from the center and the gravitational force.
Thus, the celestial bodies that glow themselves, namely the stars, glow due to the release of energy during nuclear reactions. This energy is used to contain gravitational forces and to emit light. The more massive the star, the more energy is released and the brighter the star shines.
Comets
The comet consists ofice clot, in which there are gases, dust. Its core does not emit light, however, when approaching the Sun, the core begins to melt and particles of dust, dirt, gases are thrown into outer space. They form a kind of foggy cloud around the comet, which is called a coma.
It cannot be said that a comet is a celestial body that itself glows. The main light it emits is reflected sunlight. Being far from the Sun, the light of the comet is not visible, and only approaching and receiving the sun's rays, it becomes visible. The comet itself emits a small amount of light, due to the atoms and molecules of the coma, which release the quanta of sunlight they receive. The "tail" of a comet is "scattering dust" that is illuminated by the Sun.
Meteorites
Under the influence of gravity, solid cosmic bodies called meteorites can fall to the surface of the planet. They do not burn up in the atmosphere, but when passing through it, they become very hot and begin to emit a bright light. Such a luminous meteorite is called a meteor.
Under the pressure of air, a meteor can break into many small pieces. Although it gets very hot, the inside of it usually stays cold because it doesn't heat up fully in such a short time it falls.
It can be concluded that the celestial bodies that glow themselves are stars. Only they are capable of emitting light due to their structure and the processes occurring inside. Conditionally, one might saythat a meteorite is a celestial body that itself glows, but this becomes possible only when it enters the atmosphere.
