We studied the sun last week and found a fun craft to make–a wax model. We broke up red, orange, yellow and brown crayons into small bits onto a paper plate. We then microwaved the crayons 15 seconds at a time until all were melted. Using a craft stick, we then swirled the colors around. After hardened, we added a few more shavings of yellow and orange to make solar flares and prominences. My kids thought that their suns were too red, but I think they turned out great! You could also use this idea to make the planets.
Inspired by this