Flare-Induced Coronal Disturbances Observed with Norikura "NOGIS" Coronagraph: A CME Onset

We present the first detection of a CME onset in the coronal green line emission (ion{Fe{xiv}} 5303 AA, 2 MK) by a 2D Doppler coronagraph ``NOGIS'' at the Norikura Solar Observatory, NAOJ. Different from a typical CME that evolves within a single magnetic flux system with a single magnetic neutral line, NOGIS observed a CME that evolved across two neighboring magnetic flux systems; a flare-productive active region and an aggregate of face-on coronal loops with a streamer on its top. An early precursor of the event was a density enhancement of 2 MK plasma in the space between the two magnetic flux systems. In association with an M6.5 flare that occurred at the active region, a blue-shifted upward jet and expansion appeared from a site where the legs of the two systems apparently connected each other. This expansion later evolved into a partial halo CME with an angular extent covering the latitudinal range of the two systems. These observational properties suggest the existence of sl a CME corridor that is consisted of neighboring multiple magnetic-flux systems through which a huge CME launches off.