====== Estimating the temperature ====== The temperature of a solar spot or a facula can be estimated from an intensity profile. ===== Theory ===== The Stefan-Boltzmann law gives a correlation between emitted radiative power P of a black body, the emitting area A, and its absolute temperature T: \begin{equation*} P = \sigma \cdot A \cdot T^4 \end{equation*} For details, see the relevant literature or [[https://en.wikipedia.org/wiki/Stefan-Boltzmann_law|Wikipedia]]. ===== Application ===== To determine the temperature by the Stefan-Boltzmann law, compare two radiative powers $P_1$ and $P_2$. \begin{equation*} \frac{P_1}{P_2}=\frac{T_1^4}{T_2^4} \end{equation*} As proxy of the radiative power one can use the measured count number [[en:praktikum:sonnenrandverdunklung|(see here)]].