Stars produce great amounts of electromagnetic energy in the forms of light ant heat.
It is possible to measure the intensity of star light and to use that measurement to determine the temperature of stars. The reason for doing this laboratory activity is to understand how it is possible to determine the temperature of an black body, like a star by finding the central wavelength emission of a light bulb. In addition, the energy level of a light bulb will be compared with that of an infrared source of light, which peaks beyond the visible spectrum. A black body absorbs all of the energy which strikes it, heating it until the energy being emitted equals that being absorbed. When it emits energy, it does so at all wavelengths.