The emergence and demise of stars have gone through different stages of evolution, and in the life cycle of such stars, there will also be many cosmic phenomena, such as supernova explosions and so on.
The life cycle of a star
In the process of star evolution, its life cycle is also a very complex and spectacular process, from the formation of stars to the final disappearance and death, each evolutionary stage has its own unique characteristics and key events.
In the initial stage of star formation, it is created after the collapse of the nebula. Whether they are stars within galaxies or extragalaxies, they evolved from nebulae formed by gas and cosmic dust.
These nebulae are composed of some trace elements such as hydrogen and helium, and some of the materials in the nebula will collapse under the action of gravity after accumulation, and eventually form protostars.
When the pressure and gravitational force inside the protostar can reach a balance with each other during the evolution of the star, the internal reaction of nuclear fusion begins.
At this stage, the stars have entered a relatively stable main-order stage. After the star enters a stable combustion phase, hydrogen is used as the main fuel for burning, and the reaction of nuclear fusion finally produces helium, and at the same time, the star releases a very large amount of energy.
The luminosity and temperature of a star in the main sequence phase are almost constant while generating huge energy, and the temperature and luminosity of the star will only change as the hydrogen fuel decreases, and this will move on to the next stage.
Once the hydrogen fuel in the star and the letter is burned out, the nuclear fusion reaction will gradually slow down, and the core of the star will begin to shrink with this stage, and the star will gradually heat up during the contraction.
When a star loses its inner core support, the surface of the star expands, and the star at this stage forms a red giant or red supergiant.
At this stage, the increase in surface area will significantly increase the radius of the star, and the luminosity of the star will also increase, but the temperature of the star's surface will gradually decrease due to the loss of core support.
At this time, the star is about to come to the final stage, the star with less mass, after losing fuel, there will be no nuclear fusion and other reactions inside the star, the star will eventually gradually cool, and then the volume will slowly shrink, and finally form a white dwarf.
For some massive stars, after losing fuel and no longer carrying out nuclear fusion, their evolution results are diametrically opposite, and in the final stage there will be a violent astronomical phenomenon, the outer layer of the star will be ejected, and its inner core will collapse to form a neutron star or a black hole, which will cause a supernova explosion.
No matter what stage a star goes through, it will eventually exist in the universe in another form when it dies, whether it is a white dwarf star or a neutron star or a black hole, which is the product of the star's long evolution in the process of life cycle, and there are many astronomical phenomena and key events in these stages.
Key events within a sidereal cycle
After the formation of the protostar, a huge mass and density will be formed, and the relative gravity of the star will continue to attract other matter around it, making the planet a very large molecular cloud, which is the molecular cloud stage of the star.
In the interior of the giant molecular cloud, a series of reactions such as nuclear fusion occur only after the protostellar core reaches a certain density, and at this stage, hydrogen is burned to produce helium, providing a continuous energy supply to the star.
When the star is completely formed and enters the main sequence stage, the brightness and temperature of the star will also fluctuate in the main sequence zone, and this is the evolution event of the star in the main sequence stage.
Until the star is about to age, the star will have different outcomes due to its different mass, whether it is a white dwarf or a supernova, etc., the occurrence of these events is inseparable from the evolution cycle of the star.
Supernova Bakugo
In the final moments of the star's death, because of the change in its mass and structure, a very extreme phenomenon is generated, and that is the explosion of supernova.
When the star's black cloth runs out of fuel, the star's core begins to contract and produce heat, a process that causes the star's core pressure and temperature to rise dramatically, eventually producing an unusually violent explosion.
After the explosion, the outer layers of the star will be ejected by the energy of the explosion, making the star like a huge expanding fireball, and the brightness of the entire galaxy will exceed the total brightness of the entire galaxy in the shortest possible time.
Such an eruption can sometimes last for a long time, ranging from weeks to months, during which the bursting star releases more energy than it can during its lifetime, along with a large amount of elemental energy.
These ejected shells and large amounts of elements released will eventually evolve and gradually transform into new planetary objects, etc., which are attracted to other stars or celestial bodies and become part of them.
There are two main types of supernovae explosions, one is a supernova formed by the collapse of the core, and the other is a supernova formed by a carbon-oxygen white dwarf.
The superbirth of the collapse of the core is caused by the star running out of fuel at the end of its life, and the star is unable to stabilize the balance between the inside and outside, resulting in an explosion from the inside.
The supernovae produced by carbon-oxygen white dwarfs is mainly due to the final formation of a supernova site after the explosion of some material on the surface of the star.
The explosion of supernova also has a very far-reaching impact on the evolution of the universe, and at the same time of the explosion, it can not only generate a large number of elements, but also produce very strong radiation, which will cause varying degrees of evolutionary impact on the surrounding environment.