First observation of a transitioning Type II solar radio burst using LOFAR

Type II solar radio bursts are believed to be excited by shock waves. They are often linked to shocks driven by solar eruptive events like coronal mass ejections (CMEs) and solar flares, and are characterized by a slow drift from high to low frequencies thought to reflect the speed with which the shock propagates away from the sun. Shock-excited emissions that show very little or no frequency drift are known as "stationary Type II bursts" (e.g. Aurass et al. 2002). Stationary Type II bursts are ...