The evolution of stars, the evolution of stars is

The nebula is disturbed by the outside and loses its balance, and part of the nebula disintegrates under the action of gravity, forming a rotating disk, the central region of which gradually condenses Protostars begin to form, heat up and burn and eject material outward Getting hotter and hotter, starting to glow Nuclear reactions begin A new star is born.

Similar to the aging and death of the Sun's star: the outer layers are ejected into a planetary nebula, which after a calm contraction, becomes a white dwarf, and finally becomes a black dwarf.

Aging and death of larger stars): Entering the aging phase, becoming a superred giant Becoming a supernova, throwing out a lot of matter One of the final development results is to become a neutron star The second is to form a black hole, which is also given to you.

It is suggested that LZ can be a separate "black dwarf" "supernova" ....These terms can be helpful to deepen understanding.

Nebulae Stars Supernovae Black holes (can also be black dwarfs, white dwarfs, neutron stars, determined by the mass of the star).

Stars are thought to be formed by the condensation of low-density interstellar matter. The Soviet astronomer Ambachumyan put forward the opposite view in 1955, arguing that stars were formed by a high density of pre-star material, but he did not describe the process of formation, and most astronomers did not accept this view.

The beginning of the star is an icy cloud of gas, corresponding to the right side of the spectral photometric graph (cold side). Under their own gravitational pull, these gases begin to contract. During the shrinkage process, it will gradually polymerize, so the density and pressure will increase, and the temperature will also increase; When a critical temperature is reached, hydrogen fusion occurs, and a protostar is born.

As the archetypal star continues to shrink under gravity, it becomes hotter and hotter, shifting to the left in the spectral photogram. "Stars" with a mass of less than one hundredth of the Sun eventually stop shrinking due to gas pressure.

These stars are called "brown dwarfs" or "giant planets", just like Jupiter. They do not ignite their own hydrogen, but instead dim gradually. The life cycles of these stars are represented in a downward curve in the spectrophotometric graph.

The evolution of stars is mainly divided into four periods, namely juvenile, prime, recession and death. Stars are actually macroclouds at the beginning, and in the initial stage, they are obscured by dense nebulae gas and dust, which are difficult to observe, and are called Bock spheroids. After that, the central temperature of the spherical object will be particularly high, allowing the star to begin to emit light on its own, reaching a static equilibrium.

Over time, the stars enter the middle age of the stars, forming red giants and supergiants. In recessions, stars die and may become neutron stars or black holes.

During the red giant phase, the matter inside the planet no longer undergoes thermonuclear reactions, but because the pressure on the core of the outer shell increases, it will cause other shape changes. Physics connects the internal motion of stars and the production of energy, and a change in one factor causes a change in the whole. The gas is in motion, and this movement continues under the influence of gravity, and the first stars are formed.

In the middle stage, there will be a nuclear reaction inside, and after one reaction will be completed, another reaction will begin, until all the fuel is exhausted. In the final fateful stage, perseverance still collapses or erupts under the influence of gravity, which may cause some to become nebula gas, and another part to become various other celestial objects, such as white dwarfs.

The material of most stars is gaseous, and the effect of heat conduction is not very large, so the interior is very hot. In the final stage of evolution, a small feather can cause a change in gravity, shrink stars, and cause giant molecular clouds to collide constantly. At this time, it is possible to start a non-stop explosion, causing some high-speed material to be thrown out of the star.

After that, the megamolecular cloud fragments will be broken down into smaller pieces and will drift through the universe. So the life of a star actually has a program, it seems to be very short, and the evolution time is very long, much more than the lifespan of humans.

Massive stars undergo several great changes in the process of collapsing, which is what we call a supernova explosion.

The evolution of stars is divided into these stages: the primordial nebula ——— aggregated into a primordial star, and can be burned, this stage is called the main-sequence star——— helium fusion begins to turn into carbon, this stage is called the red giant——— begins to coal, the carbon fusion begins to turn into iron, this stage the star becomes very unstable, called the Cepheid variable——— fusion completely stops, begins to contract, becomes a white dwarf and compresses the sun to the same size as the earth, it becomes a white dwarf as you can imagine, the surface gravitational acceleration of a white dwarf is very large! - The white dwarf attracts the ejected material back and triggers nuclear fusion again, and it looks like it will be n times brighter!

But it didn't take a few days to die again. This celestial phenomenon is called Nova, although it is said to be the "death throes" of the star - after the nova has exploded many times, there will be a total explosion, and the brightness will even exceed ten magnitudes. It's called a supernova explosion.

When a supernova explodes, it becomes a neutron star. Neutron stars theoretically do not have such small stars larger than 10 kilometers in diameter, and they can no longer be observed, but more than n radio emission sources have been detected in the sky, which are estimated to be neutron stars. The supernova explosion observed during the Song Dynasty is a remnant of a crab-shaped nebula, and a radio emission source in the center proves this theory.

The gravitational acceleration on the surface of a neutron star is unimaginably great, and it is estimated that there will be no less material falling back to its surface. - There is no way for the black hole to be observed, because it can't escape even light! Its existence can only be judged by gravity.

If you compress the sun to the size of a peanut, it becomes a black hole. The black hole is also constantly attracting the surrounding matter, and it is getting bigger and bigger! When it was so big that it couldn't stand the pressure inside, it began to erupt, and this thing is called a "white hole"!

The "quasars" discovered by astronomy in the 80s may be "white holes"! — Primordial matter gravitationally gathers into a primordial nebula, completing a cycle!