Observations of moving magnetic features near sunspots |
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Authors: | K Harvey J Harvey |
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Institution: | 1. Lockheed Solar Observatory, Saugus, Calif., U.S.A. 2. Kitt Peak National Observatory, Tucson, Ariz., U.S.A.
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Abstract: | The properties of small (< 2″) moving magnetic features near certain sunspots are studied with several time series of longitudinal magnetograms and Hα filtergrams. We find that the moving magnetic features: - Are associated only with decaying sunspots surrounded entirely or in part by a zone without a permanent vertical magnetic field.
- Appear first at or slightly beyond the outer edge of the parent sunspot regardless of the presence or absence of a penumbra.
- Move approximately radially outward from sunspots at about 1 km s?1 until they vanish or reach the network.
- Appear with both magnetic polarities from sunspots of single polarities but appear with a net flux of the same sign as the parent sunspot.
- Transport net flux away from the parent sunspots at the same rates as the flux decay of the sunspots.
- Tend to appear in opposite polarity pairs.
- Appear to carry a total flux away from sunspots several times larger than the total flux of the sunspots.
- Produce only a very faint emmission in the core of Hα.
A model to help understand the observations is proposed. |
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