AR12192, the largest active region in Solar Cycle 24, produced 6 X-class flares, but none of them were associated with a CME. However, a much weaker flare, of M4.0-class, was associated with a CME. Magnetic field and morphological changes are analyzed during these flares to understand why this is the case.
44 strong flares are analyzed, and a few factors are identified to determine whether a flare will be eruptive or confined.
A statistical study of sunspot region properties yields insights on why some are flare-productive.
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.