Motions around a Decaying Sunspot
Abstract
We have measured the motion of facular points and granules in the same region near a decaying sunspot. It is found that both 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 photospherical 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 is also found that granules are dragged by supergranular motions away of the moat.
- Publication:
-
Solar Physics
- Pub Date:
- September 1987
- DOI:
- 10.1007/BF00148783
- Bibcode:
- 1987SoPh..112..295M
- Keywords:
-
- Faculae;
- Plasma Decay;
- Plasma Dynamics;
- Solar Magnetic Field;
- Sunspots;
- Convection Currents;
- Filtergrams;
- Photosphere;
- Solar Physics;
- Magnetic Field;
- Magnetic Flux;
- Flux Tube;
- Horizontal Motion;
- Previous Measurement