Everything follows the same cycle thought its existences. A cycle of birth, living, and death, of a being. And though some things may not be connected, or even four light years away, like stars and humans. They still are very much the identical. Humans are born, while stars are created. Then, a Humans work through their lives: school, to a job, or work, or on personal work . On the other hand, a star's work is just being. But, through every life cycle comes death. While humans and stars die for differential reason and ways, humans and stars follow the same pattern, but just with different details. All things have a life cycle of creation, life, and dying, including the stars.
A star's birth starts with a interstellar cloud. A interstellar cloud, or a interstellar medium, is a cloud made of hydrogen gas and dust. Also, the interstellar cloud is a filled space between the other stars, that has a rattling low density (Interstellar Medium). A star forms from a interstellar cloud by combining with other atoms. With the temperature being, nothing to just above zero degrees, the atoms of the gas' start to sick together. Then the star forms in a molecular cloud. A molecular cloud, is just a thick compact of interstellar gas and dust.
Then the interstellar collapse under the gravitational force of a supernova. A supernova, as Nasa explains is “A star that suddenly increases greatly in brightness because of a catastrophic explosion that ejects most of its mass” (NASA. NASA). The collapsing of the interstellar clouds then begins so spin into a flattened disk like form. The disk becomes dense, after mixing in the center, and the temperature begins to rise. As the mixing and spinning continue and more material blends to form a protostar (Star Formation). A protostar is a star with a nuclear fusion processes that has not started. A protostar also has it's own gravity like no other, and temperature that reach to hundreds or thousands degrees. A star from form a protostar if the protostar is hot enough, dense enough, or big enough.
The life span of a star depends on the pressure of the core. Since the inner core of a star is making nuclear fusion it causes the star to expand, because of the energy and heat the nuclear fusion creates. Then, because of the star's gravity in mass, the star's mass gives off a strong power going into the star itself. So, star's mass (stellar mass) is also the determination of a star life. The pushing and pulling of the two gravity's are what give a star it's “twinkling” appearance (Educators and Students)
If the stellar mass is low then the temperature will be cold and brightness would be very dim. But, even though the stellar mass is low, it has the longest life span, a life span of ten thousand to two hundred thousand millions of years. If a star has a stellar middle mass, then the temperature of that stare will be intermediate. Also the brightness of the Middle-Mass star will be intermediate. The life span of a...