A filament-associated halo coronal mass ejection

There are only a few observations published so far that show the initiation of a coronal mass ejection (CME) and illustrate the magnetic changes in th e surface origin of a CME. Any attempt to connect a CME with its local sola r activities is meaningful. In this paper we present a clear instance of a halo CME initiation. A careful analysis of magnetograms shows that the only obvious magnetic changes in the surface region of the CME is a magnetic fl ux cancellation underneath a quiescent filament. The early disturbance was seen as the slow upward motion in segments of the quiescent filament. Four hours later, the filament was accelerated to about 50 km s(-1) and erupted. While a small part of the material in the filament was ejected into the up per corona, most of the mass was transported to a nearby region. About fort y minutes later, the transported mass was also ejected partially to the upp er corona. The eruption of the filament triggered a two-ribbon flare, with post-flare loops connecting the flare ribbons. A halo CME, which is inferre d to be associated with the eruptive filament, was observed from LASCO/C2 a nd C3. The halo CME contained two CME events, each event corresponded to a partial mass ejection of the filament. We suggest that the magnetic reconne ction at the lower atmosphere is responsible for the filament eruption and the halo CME.