Wien's law
Wien's law (also called Wien's displacement law) links the temperature of a blackbody (an ideal substance that emits and absorbs all frequencies of light) and the wavelength at which it emits the most light.
The following picture contain Wien's law formula and, plus, three examples applying it.
The stars of the first and second example are two immense stars (Rigel and Betelgeuse). They are located in the constellation of Orion:
