The magnetic field topology associated to an M6.7 flare

LUONI, M.L.; MANDRINI, C.H.; CRISTIANI, G.D.; DÉMOULIN, P.

Beijing

Congreso; 36th COSPAR Scientific Assembly; 2006

COSPAR

We study an M6 7 solar flare that occurred on October 27 2003 12 27 UT We use data in different wavelenghts magnetograms from the Michelson Doppler Imager SoHO MDI images from the H alpha Solar Telescope for Argentina HASTA and Extreme Ultraviolet Imaging Telescope SoHO EIT. We analyze the magnetic field evolution and compute the coronal field to identify the energy release site. From this study we find evidence of a magnetic null point in the corona. We relate the chromospheric and EUV brightenings to the magnetic field topology in its neighborhood. A null point at about the same location is also found in the magnetogram closest in time to the X17 flare observed on October 28 2003. The shape of bright loops observed by the Transition Region and Coronal Explorer TRACE in 195 AA during a secondary confined event accompayning the X-ray flare agrees with those of EIT during the M6 7 flare. We especulate that this null point is a stable topological structure where reconnection occurred giving raise to two sympathetic events.