Life Cycles

a) How heavy, compared to the mass of our Sun, does a star have to be for fusion to start?

b) How heavy does a star have to be to produce a supernova?

c) What force pulls regions of hydrogen together to form a star?

d) What are the huge clouds of gas in space called where this happens?

e) Briefly, what happens in nuclear fusion?

f) How old is our sun and how much longer will it stay much as it is?

g) What will happen when the hydrogen in the core starts to get used up?

h) What is likely to happen to the planets in orbit around the star when this happens?

i) Why do big stars not last as long as smaller stars?
 

When the star starts to shrink again 2 things may happen depending on the mass of the star

k) Describe what is likely to happen to our Sun and what will be left behind

l) Describe what is likely to happen to a much heavier star and what will be left behind

m) What evidence is there that black holes exist?

say what the following pictures are

all pics NASA