English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

The STEREO mission has been providing stereoscopic view of filament eruptionsin EUV. The clearest view during a filament eruption is seen in He II 304 Aobservations. One of the main problems visualizing filament dynamics in He II304 A is the strong background contrast due to surface features. We present atechnique that removes background features and leaves behind only thefilamentary structure, as seen by STEREO-A and B. The technique uses a pair ofSTEREO He II 304 A images observed simultaneously. The STEREO-B image isgeometrically transformed to STEREO-A view so that the background images appearsimilar. Filaments being elevated structures, i.e., not lying on the samespherical surface as background features, do not appear similar in thetransformed view. Thus, subtracting the two images cancels the background butleaves behind the filament structure. We apply this technique to study thedynamics of the filament eruption event of 22 May 2008, which was observed bySTEREO and followed by several ground-based observatories participating in theJoint Observing Programme (JOP 178).

A Technique for Removing Background Features in SECCHI--EUVI He II 304 A Filtergrams: Application to the Filament Eruption of 22 May 2008