Authors: Kelly Victor-French (NRL), Karl Battams (NRL), Brian Wood (NRL)

We present our investigation into the relationship between coronal brightness and the eruptivity of solar flares. Using a unique data set known as the LASCO Coronal Brightness Index (CBI), we conducted a study that explored the brightness in the lower solar corona and its relationship to the frequency and velocity of flare-associated CMEs. We analyzed all M5 and greater solar flares that took place on both limbs of the Earth-facing disk of the Sun between 1998 and 2017, explored if these flares were associated with CMEs, and recorded the projection-corrected velocity of the eruptions if they occurred. From evaluating the brightness in the corona directly over the active region (AR) source locations between 2.5 and 6.0 solar radii, we found that above a certain level of coronal brightness, the likelihood of a high-velocity CME significantly decreases. This result implies coronal brightness could be an important indicator of the eruptiveness of solar active regions.

This research was funded by the NASA STEREO/SECCHI project.