Alternate Definitions for coronal mass ejection

An outflow of plasma from or through the solar corona. CMEs are often, but not always, associated with erupting prominences, disappearing solar filaments, and/or flares.  CMEs vary widely in structure, density, and velocity.  Large and fast CMEs can approach densities of 1016 g and velocities of 2000 km/s.  Earth impacting CMEs can result in significant geomagnetic storms.

A coronal mass ejection (CME) is an ejection of material from the solar corona, usually observed with a white-light coronagraph. The ejected material is a plasma consisting primarily of electrons and protons (in addition to small quantities of heavier elements such as helium, oxygen, and iron), plus the entrained coronal magnetic field.