Abstract
An observational study of the fine structure in a sunspot region led to the following results: (a) The photosphere around a sunspot is covered with the so-called Magnetic Knots. These features have a diameter of 800 km and a magnetic field of up to 1400 gauss. Although they coincide with dark, intergranular spaces, they are distinctly different from pores. We estimate some 300 to surround the sunspot. The magnetic field of the smallest pores were found to be 1500 gauss, (b) For the Umbral Dots we find a lifetime of 25 min. Their colour, as derived from simultaneous observations at 4700 A and 6400 A, was found to be identical to that of the photosphere. Assuming their brightness to be photospheric we derive a diameter of 160 km.
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