|Solar Prominences and Filaments
|Solar Prominences and Filaments appear as dark filamentary objects on the solar disk
(filaments) and as protuberances on the edge of the solar disk (prominences). They
generally sit above magnetic neutral lines, outlining the demarcation of negative
and positive magnetic fields on the Sun’s surface. They are viewed in the H-alpha
and the Calcium K lines in the solar chromosphere. Occasionally they blow off the
surface of the Sun and can cause space weather effects on Earth if their paths intersect.
Meudon Solar Observatory has kept a record of sudden disappearances of solar filaments
for many years, publishing extensive lists in the Cartes Synoptiques de la Chromosphere
Solaire. During the International Geophysical Years (IGY 1957-1959) an international
effort to observe these disk phenomena routinely in a standard format began. This
effort continues today.