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Small-Scale Structures in Active Regions

Published online by Cambridge University Press:  12 April 2016

Christoph U. Keller
Christoph U. Keller*
Affiliation:
Institute of Astronomy, ETH-Zentrum, CH-8092 Zürich, Switzerland

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Within the last few years significant progress has been made in our understanding of the small-scale structures in active regions. Here I present some of the newest findings obtained by using speckle interferometric techniques. There exist continuum bright points with a contrast of about 30% that are cospatial with strong magnetic fields. The observations are consistent with the assumption that some facular and network bright points are the white-light signature of magnetic fluxtubes with a diameter of about 200 km. Magnetic elements larger than about 300 km are mainly darker than the average quiet sun. Their properties are similar to what has been called magnetic knots or invisible sunspots. In highly magnetic areas there is no clear relationship between continuum intensity and magnetogram signal at the smallest spatial scales. The magnetic field of pores extends beyond the dark umbra. There radially elongated structures may appear that are similar to penumbral filaments in sunspots.

Type
Session 1. Structure of Active Regions
Information
International Astronomical Union Colloquium , Volume 141: The Magnetic and Velocity Fields of Solar Active Regions , 1993 , pp. 3 - 10
Copyright
Copyright © Astronomical Society of the Pacific 1993

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