Why are sun spots dark? What color are sunspots?
September 22, 2020 | Education
| The decrease in the energy flux in the spots is due to the suppression of convective motions in the photosphere by the magnetic field. The sunspot temperature is approximately 1500 K below the temperature of the photosphere. In contrast, the spot appears darker compared to the surrounding photosphere. Given the lower temperature of the spot, its color should be red. However, this is not visually recorded, since the radiation from the spots makes up a negligible fraction of the radiation from the photosphere.
