# Temperature of glowing materials

As I understand it, Stars emit visible light, OBAFGKMRNS, in the range of $10^3 - 10^4 K$. Yet materials such as steel emit similar frequencies at much lower temps; red is around 800K. Why the difference? I thought black body radiation applies to all materials and environments. I am an interested amateur.

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The peak wavelength at which a body emits light is governed by Wien's displacement law, which states that this wavelength is inversely proportional to the temperature, as $$\lambda \, T=\text{const}=0.003\text{ m K}.$$ More graphically, in the stellar-surface sort of temperature range, this looks like
You'll notice that although the short-wavelength cut-off is rather sharp, bodies still emit light at shorter wavelengths than the Wien peak wavelength. Thus for steel at 800 K the peak wavelength is at 3.7 $\mu\text{m}$, in the mid-infrared. The total radiance on the visible range is then proportional to some power of $(700\text{nm}/3.7\,\mu\text{m})\approx 0.2$, so it's about 1% or less.