Features of coronal mass ejections of minimum size

Abstract

The coronal mass ejections (CME) with small angular dimensions (d ≤ 10°) have the simplest form, much simpler than large CME. This fact simplifies the problem of analyzing the CME structure and studying their origin. On the basis of the analysis of the LASCO C2 (SOHO) data, we show in this paper that the motion of a CME having small dimensions proceeds within a magnetic tube (a ray with increased brightness) of the streamer belt and leads to an “explosion-like” increase in the angular dimensions (rapid expansion) of the tube. A hypothesis is put forward that a small CME represents a “plasmoid” (a plasma bunch bounded in space, with its own magnetic field) thrown into the base of the magnetic tube and moving along it away from the Sun.