Two homologous circular-ribbon flares associated with two filament eruptions were observed and analyzed. The emergence of magnetic flux ropes helped to inject free energy into the region and drive the magnetic reconnection above it.
Rapid and irreversible changes in chromospheric magnetic field during a flare have been observed for the first time. They look surprisingly different from their photospheric counterpart.
New HMI high-cadence vector magnetograms are now available. Observations every 135 or 90 seconds reveal the rapid magnetic evolution occurring during major solar eruptions.
A statistical study of sunspot region properties yields insights on why some are flare-productive.
An atypical X-shaped-ribbon flare provides evidence for 3D magnetic reconnection at a separator.
A statistical study using HMI vector magnetograms predicts the fastest CME that an active region can produce based on its magnetic parameters.
AR 12192 produced six X-class flares, but none was associated with a CME. HMI observations reveal the mild nature of the giant. It has weak relative non-potentiality and strong overlying field; the confined X3 flare leaves little imprint on the photosphere.
Combining the outstanding capability of HMI/SDO and NST/BBSO, we studied two rarely observed three-ribbon flares. The flaring site is characterized with an intriguing “fish-bone”-like morphology. These results are discussed in favor of reconnection along the coronal null-line.
We examine the polarization of light emitted by a loop prominence system, near the Fe I line (6173 Å). It has a linearly polarized component, at times up to the level expected from pure Thomson scattering.
Analysis of HMI vector magnetic field data before and after a flare illustrate how the energy released can result in a collapse of loop structures, and how the effects can be observed on the solar surface.