Search for the stars
If observed, the first question is the night sky is a restless mind: what is a star? A star is a big ball of hot gas and bright, produces the own energy through so-called nuclear reactions that take place core Center of the huge temperatures reach the star in the and appear as luminous phenomenon that accompanies us on our observations of the night sky on a clear night.
Stars have a lifecycle as all living things are born, grow to develop and grow and eventually die and disappear more or less violent, such as an explosion of supernova that can trigger the process of the birth of new stars. But it happens so slowly that they can be seen in the human timescale.
The universe is an almost infinite space place for millions of stars, star clusters and galaxies rated,. The distance from the Sun, which is the nearest star to Earth is called the astronomical unit, AU and amounts to 149,597,870 km. Since the speed of light is 300,000 km per second, about eight minutes to reach Earth is observed from the Sun of visible light. The next nearest star to the Sun is Proxima Centauri, and the emitted light takes over 4 years in which to reach Earth. This means that if you look at the stars, "see" as it was more than four years and not know how in this day and age. And in fact, if you observed the Sun with the right eye protection, it "sees" what was it about eight minutes.
Molecular clouds
On clear nights in particular in the field with a small telescope, far away from cities or towns, which illuminate the night sky considered see also areas of fog you where rated stars, which are born in the constellation of the same name Orion or M42. These are called molecular clouds.
Molecular clouds are very large and deep dark clouds, which are formed by a gas hydrogen (99%) and interstellar dust in a very small proportion (1%) called, but enough, so that the star may be born under certain conditions. One could say that the raw material of star formation provide for these clouds.
The embryos of future stars within the molecular clouds are hidden and only the radio and infrared waves of the electromagnetic spectrum emitted by these embryos of stars, through these dark areas - not the visible light. We can with suitable devices such as telescopes in space or radio antennas on ground-based observatories interpretation of the results of the data and develop a theory of the formation of stars.
The birth of a star
Although the proportion of dust in the small compared with the amount of gas is cloud material, these clouds are so extensive, yes millions of stars like the Sun to sufficiently produce thousands mass gather.
The education process is raised, if for some reason, there is a 'fragmentation' of the cloud, they break with enough to start density relationship between the amount of weight and the occupied band in fragments slowly shrink. The reason being is a close Supernova - the final phase of the stars with large mass - can be the arrival of a shock wave from the explosion mentioned above from a fragmentation.
This process is irreversible, the fragment cloud continues to contract and be orders of magnitude larger than the original cloud - fragment - from those to a value twenty is enough mass to start, the force of gravity acting poet, make reduced so that it under its own weight collapses the cloud. This event is the core of the Star: Protostar that clouds continue to fall on the rest of the field of fragment.
As material still in the Protostar fall, it begins to rotate, pushing matter jets (such as geysers) long distances and, so that turns the Protostar is not too fast, which would cause high speed their disintegration.
Due to this initial rotation is preferred in the Equator Protostar the matter of the cloud, form, what is known as a drive, role, orbiting the Protostar, and which may be the seed of a future system of the planet to filed it, similar to how the solar system.
This first phase of the star formation takes about 100,000 years and how it is darkened by the dust cloud. We have to use, as mentioned above, telescopes (capture the emission of radio waves) or infrared detect radio telescopes at this time. Then is visible as the material on the Protostar and fragment of shell falls gas and dust cloud dissipates, the embryo. The collapse happens in a Sun-like Star a million years after the start of the process.
A new star
After ten million years, the first process of contraction of the collapse of gravity at the end. During this time, the temperature of the Protostar has grown enormously, and this temperature is so high that the collapse at the end of the thermonuclear reactions start happening with hydrogen as fuel in the core of the star, making it a heavy element with the name helium. At this point, we can say that a new star is born and main sequence is referred to as a phase of life.
The star is stable, as it is known as hydrostatic equilibrium in a State: the power, the outward (the pressure of the energy produced by nuclear reactions) presses is through the power of gravity to the inside, pushes balanced.
