Chromospheric activity in sunspot light bridges. Issue 10 (November 2016)

• Record Type: Journal Article
• Authors: Louis, R. E.
• Other Names: Denker C. sponsoringEditor.; Louis R. sponsoringEditor.; Mann G. sponsoringEditor.
• Is Part Of: Astronomische Nachrichten. Volume 337:Issue 10(2016)
• Page Start: 1033
• Page End: 1039
• Publication Date: 2016-11
• Subjects: Sun: chromosphere Sun: photosphere -- sunspots -- techniques: high angular resolution -- techniques: polari‐metric; Astronomy -- Periodicals; 520.5
• DOI: 10.1002/asna.201612429
• Languages: English
• ISSNs: 0004-6337

Abstract

Abstract: High‐resolution filtergrams from Hinode were used to analyse the nature of chromospheric activity over a set of five sunspot light bridges. The broad‐band CaII H filtergrams depict a variety of phenomena which include large arc‐shaped brightenings, bright patches, and small‐scale jets. These strong brightenings are recurrent over a duration of several hours and appear to be a common attribute of a sunspot light bridge, independent of its photospheric morphology and horizontal flow pattern. Hinode spectro‐polarimetric observations were used to construct far wing magnetograms from the FeI line at 630.25 nm, which reveal the presence of small‐scale magnetic and velocity inhomogeneities in the photosphere of the light bridges. Although there is strong evidence for a causal relation between the photospheric anomalies and the observed chromospheric activity, the physical mechanism responsible for the latter remains speculative. (© 2016 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)