Impressive filament eruption
posted: April 9, 2015

A movie of this event can be found here.

In absence of any large or complex sunspot group, this week's main event was another spectacular filament eruption. This eruption took place late on 4 April and was associated with a long duration C3.8 double ribbon flare that started at 22:16UT, peaked at 00:07UT, and ended at 01:45UT. "Double ribbon" here means that there are two bright ribbons parallel and along the location of the ejected filament.


The image above as well as the top part of figure underneath shows the combined view in extreme ultraviolet (EUV) from the SDO AIA 193 (green; 1.3 million degrees) and AIA 304 (brownish; 80.000 degrees) filters. In the bottom part, a magnetogram is overlaid showing how the filament is squeezed between magnetic fields of opposite polarity (yellow: positive, coming out; blue: negative, returning to the solar interior). The filament is indicated in red, and the filament channel is red-dashed.


The first three clips in the movie show the evolution of this filament eruption in the above mentioned filters, as well as a zoom. It shows the untwisting of the filament as it erupts, and the obscuration of the underlying solar atmosphere by the ejected material. Also, the series of post-eruption coronal loops -a so-called "arcade"- are well visible, with their footpoints rooted in the elements of opposite magnetic polarity along the filament channel.


The last two clips of the movie show the evolution of the eruption in AIA 193 and a difference movie (one image subtracted from the previous). The latter provides a more detailed view on the specifics of the eruption, in particular the movement of material all along the filament channel as annotated in the images underneath.


Credits - Data and imagery for the movie clips were taken from SDO and JHelioviewer.