This is hot enough to emit black-body radiation in the X-ray spectrum.
In 1894 Planck turned his attention to the problem of black-body radiation.
Wien proceeded to study the characteristics of this black-body radiation.
Planck's law of black-body radiation follows immediately as a geometric sum.
The most common light sources are thermal: a body at a given temperature emits a characteristic spectrum of black-body radiation.
He also formulated an expression for the black-body radiation which is correct in the photon-gas limit.
If you remember your black-body radiation, black is actually best in heat.
The colour of simple incandescence is due to black-body radiation.
The radiation of such perfect emitters is called black-body radiation.
With all these assumptions in place, the star emits black-body radiation at the temperature of the photosphere.
