Sunspot intensities and their correction for scattered light

Photoelectric measurements of monochromatic spot intensities obtained with the domeless Coudé refractor in Anacapri are given. The scattered light superimposed on the spot, as deduced from measurements outside the sun's limb, amounts on the average to about 4% of the photospheric intensity. The accuracy of the derived spot intensities is better than 10%. Two of four investigated spots yielded temperatures below 3900K (ΔΘ > 0.5).