Origin of Helical Coronal Disturbances from the Sun

Abstract

By combining data from the Nobeyama Radioheliograph and the LASCO coronagraph aboard the SoHO spacecraft, we report two helical coronal disturbances accompanying white-light coronal mass ejections (CMEs). These are activated prominences at the base, rotating around each vertical axis while moving on the solar surface with projected speeds of >=50 km s^-1. The activity continues in a CME core and in a neighboring streamer growing over 6 R_solar. Neither flare activity nor radio bursts were observed during the two events. We suggest that the apparent presence or absence of a CME core depends on the density of the eruptive material associated with the CME.