The prize recognises work which started with Spruit's thesis at the University of Utrecht. At the Max Planck Institute for Astrophysics he has worked on X-ray binaries, gamma-ray bursts and magnetic fields in stars. Recently he has returned to solar physics with work on the structure of sunspots.

The AAS awards the prize annually to a scientist for outstanding contributions to the field of solar astronomy. It is named after the American astronomer George Ellery Hale (1868-1938), who discovered (in 1908) that sunspots are the seat of strong magnetic fields. He was also the driving force behind the construction of ever larger telescopes including the famous 200" telescope on Mount Palomar, until 1975 the world's largest telescope.

The award ceremony will take place in May at the spring meeting of the American Astronomical Society in Boston.