Astronomy Help?

Question

2 questions:
In which group are the stars most varied in both size and luminosity?
and
What will eventually happen to our sun?
Thank you

Answer 1

Not sure what you mean by group? Cluster? Galaxy?

If it follows the normal course of stellar evolution for Main Sequence stars, the Sun will get larger when it is another 4-5 billion years old, as it runs out of hydrogen to fuse in its core and starts to fuse helium instead. It will enter a phase of being a red giant for about 100 million years and consume the inner planets as it does so. It will shed a lot of mass, ending its days as a white dwarf, dwindling to about the size of the earth and much cooler than it is now.

Even is colonies had meantime established themselves on the moons of the outer planets, it is doubtful that they would be able to get enough heat and light from a white dwarf star to survive.

Answer 2

First question would seem to be about the HR diagram... so, I'd guess your answer should be the group of stars included in the Main Sequence are the most varied.
http://en.wikipedia.org/wiki/Main_sequence

The HR Diagram
http://en.wikipedia.org/wiki/Hertzsprung-Russell_diagram

About what happens to our Sun... there's a nice diagram at the top of this page: http://en.wikipedia.org/wiki/Stellar_evolution
It shows the life cycle of the Sun... with additional details below, of course :)

Hope this helps,

JT

Answer 3

The first question isn't clear - what groups are you choosing from?

The sun will swell up into a red giant, then die and become a white dwarf, possibly surrounded by a planetary nebula.