Supergranular motions around a decaying sunspot

The motion was measured of facular points and of granules in the same region near a decaying sunspot. It is found that both solar features move away across the moat surrounding the sunspot. The mean speed of facular points is larger than that of granules: 0.65 km s-1 and 0.4 km s-1, respectively. These results are consistent with previous measurements of the speed of bright network features and moving magnetic fields, as well as of non-magnetic photospheric material. They support models in which a decaying sunspot is at the center of a supergranule, whose horizontal motions sweep out granules and magnetic flux tubes associated to the facular points. It was also found that granules are dragged by supergranular motions away from the moat. (author). 2 figs., 8 refs