The largest flares of solar cycle 24 as potential clues for stellar superflares

by Paolo Romano

Hosted by University of Catania / INAF - Catania Astrophysical Observatory on September 26, 2019


The peculiarity of two homologous white light solar flares occurred on 2017 September 6th, in the super active region NOAA 12673, will be described.
The strong and persistent shear motion of the photospheric structures, together with the high intensity of the magnetic flux involved in these events, can be considered responsible for the huge amount of energy continuously supplied in the higher levels of the solar atmosphere. Moreover, their white light emission and released energy can be attributed to the special magnetic field topology of the active region, suitable for the occurrence of magnetic reconnection at low altitudes. These events have been adopted as a hint for a possible interpretation of the extremely energetic flares, named “superflares”, recently reported by the Kepler mission on young G-type stars. In fact, the main characteristics of cooler G−type stars recall the main ingredients at the base of these solar flares, i.e., high strength of the magnetic field and strong horizontal velocities.