In three or four paragraphs is required to discuss the real
Solution
The life-cycle of a star greatly depends on its mass. Further, a star\'s life cycle is determined by its mass. The larger its mass, the shorter its life-cycle. Again a star\'s mass is determined by the amount of matter that is avialable on its nebula, the giant cloud of gas and dust from which its was born. Over time, the hydrogen gas in the nebula is pulled togather by gravity and begins to spin. As the gas spins faster, it heats up and becomes a protostar. Eventually the temperature reaches 15000000 degress and the nuclear fission occurs in the core of cloud. The cloud begins to glow brightly, contracts a little and becomes stable. It is now a main sequence of star, and remains in this stage, shining for millions to billions of years to come. This is the stage our sun is at right now.
Further, for a star less than or equal to the solar mass of our sun, after the main sequence it will expand to a red giant. Gradually over time it will slowly dissipate and all that will remain is a white dwarf that slowly burns out and becomes a black dwarf. Stars that have between 2-5 times the solar mass of our sun will grow into red giant again however instead of becoming a white dwarf, the star as enough mass that collaspes in on itself to a point and then blows out in what is called a supernova. The remains of a supernova are planetary nebulas. Massive stars that are >5 solar masses form red supergiants and subsequently collaspe on themselves just as with the previous group, except however it is so massive that it can\'t stop the force of gravity from stopping the collasping process and forms a black hole.
