Some 5 billion years from now, our Sun will gradually expand into a red giant. By then, perhaps, our space-faring descendants will have migrated to safety!

http://observe.arc.nasa.gov/nasa/space/stellardeath/stellardeath_opening.html
Stellar Evolution and Death: life cycle of stars and additional information.

http://amazing-space.stsci.edu/light/stellarEncounters-frames.html
Amazing Space: an activity on identifying the temperature of stars based on color.