Solar prominences observation by Deslandres, 1894. The main disc of the Sun has been blocked out by a filter, revealing the solar prominences rising from the Sun's surface. The prominences are large amounts of plasma being ejected from the Sun's surface by turbulence in its magnetic field. This observation was made on 31 May 1894 by French astronomer Henri-Alexandre Deslandres (1853-1948). The technique here uses a coronagraph attachment to a telescope.