New images from the Swedish 1-meter Solar Telescope on La Palma show
the presence of magnetic waves, Alfvén waves, in the lower solar
atmosphere. The authors, a collaboration of scientist from Queens
University, Belfast, the University of Sheffield, and California State
University Northridge, conclude that these waves could heat the solar
corona, which would explain the coronal temperature of
1 million K or more, while the solar surface, the
photosphere, is "only" 6000 K.
Alfvén waves are named after the Swedish physicist and Nobel laureate Hannes Alfvén, who developed his theory of these magnetic waves already in the 1940s. The Swedish physicist Bengt Edlén did ground breaking contributions to establishing the high coronal temperature by showing that spectral lines that were assumed to be associated with unknown elements were in fact from highly ionized iron, stripped of many of its electrons by the extreme temperatures. Bengt Edlén received international recognition for his important contributions to the explanation of the coronal temperature in 1945 and in 1968.