Image of the week - What do these pictures have in common?

Photo courtesy SOHO

In answer to our question, all of these images are of our sun, and were taken by SOHO — the Solar and Heliospheric Observatory, a project that is an international collaboration between the European Space Agency and NASA to study the sun from its deep core to its outer corona and its solar wind. Many of the images were modeled using a synthetic modeling program that allows astronomers to determine the temperature of surface layers, the sun’s chemical composition, and the relative abundance of the various elements. Known as SYNTSPEC, the modeling program is run on Baltic Grid and Lit Grid. (Click to enlarge.) Image courtesy SOHO