Solar prominences. Artwork of prominences on the surface of the Sun. Prominences are clouds of ionized gas (plasma) which stretch between the Sun's chromosphere and corona. The prominences' shapes are determined by strong, localized magnetic fields. Prominences have a higher density and lower temperature than their surroundings. They may remain stable for several months or change their structure over a few minutes. They are typically a few hundred thousand kilometres long and several thousand kilometers thick.