Radio spectrum of two active regions

The results of the total solar eclipse of November 12, 1966, observed at 8 different wave-lengths between 3 and 21 cm, are studied and the spectrum of two active regions present on the disk is deduced. It is shown that the observed increase of the flux of the most intense source in the range 3–10 cm is due to geometrical effects. Neglecting the influence of the magnetic field, the following quantities are deduced.

1. the mean and central temperature of the coronal condensation.
2. the ∫ _corona N ²dh (N = electron density).

Both these quantities are in good agreement with optical observations.