Solar prominences are clouds of charged particles ("plasma") above the solar surface squeezed between magnetic regions of opposite polarity. Being cooler and denser than the plasma underneath and their surroundings, they appear as bright blobs when seen near the solar limb and as dark lines when seen on the solar disk (then they are called "filaments"). Special filters are required to observe these features, such as in the Hydrogen-alpha (H-alpha) line in the red part of the solar spectrum, or in some extreme ultraviolet (EUV) passbands.
A rather large prominence started to round the northeast limb on 1 April and towered over 120.000 km or about 10 earth diameters above the solar surface 2 days later. The feature was highly active and, combined with its staggering height, finally erupted early on 4 April. It was associated with a very nice coronal mass ejection (CME) showing the three typical parts of a CME: a bright frontal loop surrounding a dark cavity and the core filament. Often, this kind of structure is reminiscent of a light bulb. The CME was not directed to Earth.
Using SDO and SOHO/LASCO imagery, a movie was created first showing a full disk and a zoom of the eruption in EUV (AIA304 and AIA193), followed by coronagraphic imagery of the associated CME.
 |
 |
