Over the centuries a series of classic experiments in optics and chemistry--some of which you can find online at this site and try for yourselves--established the nature of the stars and our Sun.

Herschel: The discovery of infrared

NASA's Infrared Processing and Analysis Center Infrared Astronomy web site.

From PBS's "Newton's Apple": infrared Radiation: Interesting at home experiment on infrared radiation using a television remote control to detect infrared radiation.