# Measuring the interior temperature of the Sun

We frequently measure the "temperature of the Sun" using Wien law: $$\lambda_m T = b$$ where $$b$$ is the displacement constant, $$\lambda_m$$ is the peak wavelength obtained from the spectrum, and $$T$$ is the corresponding temperature. Using this method $$T$$ comes out to be ~$$6000$$ K - which is the surface temperature of the Sun, obviously. So, is there any physical reason that we are getting the surface temperature of the Sun, and not getting the interior temperature of the Sun, by this method? Also, is there any way by which interior temperature can be measured using Wien law or Blackbody radiation theory?