Streamer
Streamer belt seen in the field of view of the LASCO C2 coronagraph. The upper panel shows the current sheet during a quiet period; the lower panel shows the same area two days prior to the February 3 CME. The obvious increase in brightness prior to the CME indicates that more material is stored before a global coronal disturbance than during quiet coronal periods. It is assumed that the current sheet will blow open when the pressure inside exceeds a certain value. An instability will then accelerate and release the stored hot coronal material as a global coronal disturbance. Upper panel: during a quiet period. Lower panel: during an active period prior to a coronal mass ejection. The field of view covers 1.6 to 6 solar radii.