Like any body in nature, the stars, too, can not remain unchanged.They are born, develop, and finally "die".Evolution of stars takes billions of years, but over time their education debate.Previously, astronomers thought that the process of "birth" of stardust requires millions of years, but has recently been received photos from the region of the sky Great Orion Nebula.For several years, there has arisen a small star cluster.The pictures
1947 this place was fixed a small group of star-like objects.By 1954, some of them have become elongated, and five years later, these objects collapsed into separate.So the first time the process of star birth is literally in front of the astronomers.
Let's analyze in detail how the structure and evolution of stars, how to begin and the end of their endless, human standards of life.
Traditionally, scientists have suggested that stars are formed from the condensation of clouds of gas and dust environment.Under the influence of gravitational forces formed from clouds formed an opaque ball of gas, compact in structure.Its internal pressure can not balance the gravitational forces compress it.Gradually balloon shrinks so that the temperature rises stellar interiors, hot gas and the pressure inside the balloon balance the external force.Thereafter, the compression terminates.The duration of this process depends on the mass of the star and typically from two to several hundreds of millions of years.
structure of stars suggests a very high temperature in their interiors, which contributes to incessant thermonuclear processes (hydrogen, which forms them, is converted into helium).These processes are responsible for the intense radiation of stars.Time for which they use the existing stock of hydrogen is determined by their weight.From the same and depends on the duration of the radiation.
When hydrogen reserves are depleted, the evolution of stars coming to the stage of the formation of the red giant.This occurs as follows.After the cessation of energy gravitational forces begin to compress the core.This star is greatly increased in size.Luminance also increases as the process continues fusion reactions, but only in a thin layer at the boundary.
This process is accompanied by a rise in temperature of the helium core contracting and converting helium nuclei in the carbon nucleus.
According to forecasts, our sun can turn into a red giant eight billion years.The radius of it at the same time will increase by several dozen times, and the luminosity will increase by hundreds of times compared with current levels.
Lifespan star, as already mentioned, depends on its mass.Objects with a mass that is less sunny, very sparingly "spend" its nuclear fuel supplies, so can shine tens of billions of years.
evolution of stars ends with the formation of white dwarfs.It happens to those of them whose mass is close to the mass of the Sun, ie,does not exceed 1.2 on it.
Giant stars are usually quickly deplete its supply of nuclear fuel.This is accompanied by a significant weight loss, particularly due to the discharge of the outer shells.As a result, there is only gradually cools the central part, in which the nuclear reaction stopped completely.Over time, these stars will cease to light and become invisible.
But sometimes normal evolution and structure of stars disrupted.Often it concerns massive objects, having exhausted all types of thermonuclear fuel.Then they can be converted into a neutron, supernovae or black holes.The more scientists learn about these objects, the more new questions arise.
