Prof Keenan’s research interests span a range of areas, including solar and stellar astrophysics; plasma physics (including the study of astrophysical-type plasmas in the laboratory, and research on magnetically-confined tokamak plasmas for fusion work); spectral modelling of astrophysical plasmas using atomic physics data generated at Queen’s University.

His research has attracted funding from numerous sources, including the UK Science and Technology Facilities Council, UK Engineering and Physical Sciences Research Council, AWE Aldermaston, UK Atomic Energy Authority, the Royal Society, Leverhulme Trust and EU.