The dictionary defines a star as : "any of the heavenly bodies,except the moon, appearing as fixed, luminous points in the sky at night". In the galaxy in which we live ( Milky Way), there are estimated about 300 billion stars. So to recap, just in one galaxy alone, there are 300 billion stars! In the whole, known universe, there are about one hundred billion galaxies. The number of stars is almost immeasurable.
Star Formation:
Stars form from a cloud of particles, which is called a molecular cloud. Actual star formation begins when the cloud collapse on it's self from it's own gravity. When the cloud collapses, atoms start to bind together and begin to create their own gravitational force on other atoms. Once the clump breaks away from all of the other ones and has it's own gravity, this is when it is considered a Prostar.
Star Formation:
Stars form from a cloud of particles, which is called a molecular cloud. Actual star formation begins when the cloud collapse on it's self from it's own gravity. When the cloud collapses, atoms start to bind together and begin to create their own gravitational force on other atoms. Once the clump breaks away from all of the other ones and has it's own gravity, this is when it is considered a Prostar.
As the clump attracts more atoms, the denser and opaquer it becomes. (This is a direct relationship.) As the temperature and pressure become more intense, infall will stop. Stellar wind will causes infall to cease. (Infall is oncoming atoms and debris.) After this, the star will live for a very long time. The average lifetime of a star is between 1 billion to 10 billion years old.
Quiz
1.True or False: Stellar Winds have the same effect on stars that Earth's magnetic field has on it.
2.Complete the sentence: Early stars are considered .
3. Stars form from .
4. Infall is .
5. True or False: Stars only live for 10 years.