Speaker
Eun-Kyung Lim
(Korea Astronomy and Space Science Institute)
Description
The evolution of a series of confined C-class flares and an eruptive M-class flare
observed by the Hα filtergraph of New Solar Telescope (NST) at Big Bear Solar
Observatory (BBSO) was studied in supplemented with both the Atmospheric Image
Assembly (AIA) 304 Å data and Helioseismic and Magnetic Imager (HMI) magnetograms
provided by Solar Dynamics Observatory (SDO). During the initial phase of confined
C-class flares, Hα observations showed that the curtain-like structure formed behind
the drifting inverted Y-shape jet with a subsequent brightenings near the footpoint
of the drifting jet. Then a blowout eruption accompanying helical structure occurred
with the onset of the M-class flare. Analysis of HMI magnetograms revealed that the
negative flux continued to emerge in the interested positive polarity region with the
magnetic helicity large enough for roughly 2 CMEs before the flare onset. Based on
these results, we suggest that both accumulation of magnetic helicity through the
flux emergence and repeated successive reconnections in the chromospheric layer
played important roles in destabilizing the sheared magnetic field and thus driving
the blowout eruption.
Primary author
Eun-Kyung Lim
(Korea Astronomy and Space Science Institute)
