A star radiates light across the electromagnetic spectrum in what is known as a spectral intensity distribution. Because each star's surface has a characteristic temperature, the resulting spectral intensity distribution approximates that of an ideal blackbody. In the figure, the theoretical blackbody curves for three stars of differing surface temperatures are plotted. Here, the sizes of the idealized stars can be assumed to be equal.
Star A: 30,000 K
the star appearing bluest
the star with maximum intensity at ultraviolet wavelengths
the star appearing brightest
Star B: 10,000 K
the star whose equal intensities measured through yellow (V) and blue (B) filters
Star C: 3,000 K
the star appearing reddest
the star with maximum intensity at infrared wavelengths