Physics
Blackbody Radiation Spectrum
Quick fact
The Sun's surface temperature (~5,500°C) causes its blackbody spectrum to peak in the visible range, but a cooler star like Betelgeuse (3,500°C) appears red because its spectrum peaks at longer wavelengths.
Why this is interesting
Ever noticed how a metal glows red when heated, then orange, then white? That's the blackbody radiation spectrum in action. But why does the color change with temperature?