Astar 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. note that the yellow filter in the figure is marked "v" for "visual".