SIMPLE EXPLANATION:
Step 1: The dust and gas from a nebula group together.
Step 2: When this group is big enough, energy is created - this group starts to shine.
Step 3: Then it reaches the size of a star.
Step 4: This star becomes a Red Giant - about 500 or more times as big as the Sun now.
Step 5: When the Red Giant runs out of its energy, it explodes as a supernova.
Step 6: This supernova leaves behind a little (50 km across) and dens star - white dwarf.
Step 7: If the Red Giant weighed at least twice as much as our sun, this white dwarf turns into a neutron star and then into a black hole. This whole step occurs in less than a minute.
(Step 8: If a really huge and dens star gets sucked into a black hole, a quasar might have formed)
Note 1: The lifecycle of a star lasts about 10-15 billions of years.
Note 2: Step 8 only may never occur in the lifecycle.
cause its life cycle appearence
As stars burn, they shed matter, becoming less massive slowly throughout their life cycle. This reduction in mass necessarily lessens their gravity, causing the stars' diameter to increase. So, many end-stage stars will be huge and bloated. Massive red giant stars are examples of this.
http://images.google.com.au/images?q=lifecycle+of+a+star&um=1&hl=en&rlz=1T4HPAB_enAU255AU259&sa=2
life and death or sun and black hole
The most important factor is the stars mass.
A chicken has 3-stages life cycle, not 4 -stages life cycle
There is no animal that has 2 stages of life cycle. Most animals have at least 3 stages of life cycle.
The frog has three distinct stages of development in its life cycle.
What are the main stages of an animal life
1 life cycle that has 4 stages.
There is 6 stages in a parrots life cycle
2 stages
they have five stages
3 stages
2 stages
it has 3 stages
There are 5 general stages in the family cycle.