The temperature of penumbral filaments

The intensity of individual penumbral filaments has recently been measured at the Pic-du-Midi Observatory as well as from observations obtained during the third flight of the Soviet Stratospheric Solar Station. We have used the results of these measurements to calculate the corresponding average penumbral intensity as function of wavelength. The calculated average intensity is compared with the average intensity observed at the Oslo Solar Observatory. The Pic-du-Midi observations are supported by this comparison. The run of temperature versus optical depth is given for bright and dark penumbral filaments.The variation of gas pressure with geometrical depth is discussed. It is suggested that the magnetic field direction has a different variation with depth in bright and dark filaments.