Lots of cool science experiments and such. And for my little ones, I found this arts and crafts sheet that I figured would help them enjoy learning about this super star. (Pictured below and can be found at this link: http://www.speakaboos.com/worksheet/arts-and-crafts/sun-plates)
Also, please do not forget that signs of the end times include the fact that the "Sun/Shemesh will be darkened." So you may want to include solar eclipses into your unit study. Here is the variations of Joel 3:15 and several cross references to the darkening of Shemesh (the Sun): http://bible.cc/joel/3-15.htm
What I love doing is learning about the physical properties of an object/concept then trying to ascertain the spiritual truth to the creation. Could be a fun and enlightening creative writing project!
That's all for now. Happy learning, ladies!