What is a coronal mass ejection (CME)?

What is a coronal mass ejection (CME)?

• A. When the Sun's magnetic field is stretched and chunks of the Sun's surface are ejected into space
• B. A solar wind stream of protons and electrons
• C. A sunspot rotation event
• D. A solar flare that emits gamma rays

Answer: (A)

A coronal mass ejection is a large eruption of magnetized plasma from the Sun’s corona into space, driven by changes in the Sun’s magnetic fields. It happens when magnetic field lines in active regions become stressed and snap into a new configuration, flinging a bubble of charged particles outward. This is a discrete, massive release, unlike the steady solar wind that continually streams from the Sun. It’s also not simply a sunspot rotation event, which refers to the movement of magnetic regions on the Sun’s surface, nor is it just a solar flare (a rapid burst of radiation); flares can accompany CMEs, but the defining feature of a CME is the actual ejection of material and magnetic field into space.

A coronal mass ejection is a large eruption of magnetized plasma from the Sun’s corona into space, driven by changes in the Sun’s magnetic fields. It happens when magnetic field lines in active regions become stressed and snap into a new configuration, flinging a bubble of charged particles outward. This is a discrete, massive release, unlike the steady solar wind that continually streams from the Sun. It’s also not simply a sunspot rotation event, which refers to the movement of magnetic regions on the Sun’s surface, nor is it just a solar flare (a rapid burst of radiation); flares can accompany CMEs, but the defining feature of a CME is the actual ejection of material and magnetic field into space.