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Evolution of Structures in the Bright Hα Network

Published online by Cambridge University Press:  14 August 2015

Dainis Dravins
Dainis Dravins*
Affiliation:
Lund Observatory, Lund, Sweden

Abstract

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We present off-band Hα filtergrams showing the bright Hα network (solar filigree) and its evolution, with subarcsecond resolution. In quiet regions the total area covered by elements in the network is constant over periods of hours but changes in the geometry are observed over 10 min (the timescale of granule and dark mottle lifetimes), that can be interpreted as due to (macro)turbulent horizontal velocities of about 1 km s-1. The network can be resolved into strings of tiny bright dots; on the order of 100 per supergranule cell boundary. These dots may mark the location of magnetic filaments. The contrast of the features is higher in the blue than in the red wing which may indicate that in the lower chromosphere, the downdraft at supergranule boundaries does not occur in the bright crinkles themselves but rather adjacent to them.

Type
Part VI: Evolution of Chromospheric Fine Structures
Information
Symposium - International Astronomical Union , Volume 56: Chromospheric Fine Structure , 1974 , pp. 257 - 261
Copyright
Copyright © Reidel 1974 

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