The X3.8 flare in NOAA 10720 : a new example of the domino effect
Abstract
We have studied an X3.8 flare occurred in NOAA 10720 on 17 January 2005 using chromospheric and photospheric images acquired at INAF - Catania Astrophysical Observatory, TRACE images acquired at 1600 ?, full disk MDI magnetograms, RHESSI hard X-ray data and Ondrejov radio data, in order to investigate the morphological and magnetic evolution of the active region before and during the flare. The analysis of H-alpha and 1600 ? images showed that initially a two-ribbon structure developed in the central part of the active region, later two bright ribbons (in the most eastern side) and a strong brightness increase (at the western boundary of the active region) were observed contemporarily. In the following time interval a new pair of ribbons was observed in the central-western side of the region. The analysis of the magnetic configuration and the location of a null point allowed us to single out the sites where magnetic reconnection processes were most likely to occur. Based on this result and on the analysis of H-alpha, TRACE, RHESSI and Ondrejov data, we interpreted this behavior as due to an initial filament eruption that occurred in the central part of NOAA 10720, where the null point was located, and later on, as in a domino effect, other filament destabilization or eruption took place in the eastern and western part of the active region.
- Publication:
-
Solar Heliospheric and INterplanetary Environment (SHINE 2010)
- Pub Date:
- July 2010
- Bibcode:
- 2010shin.confE..16F