 Besides determining the unique properties of the highly energetic emissions from gamma-ray bursts – the brightest and most powerful cosmic events ever documented – Kouveliotou was part of the team which in 1997 revealed the extragalactic nature of these sources.In 1998, she and her team also made the first confirmed detection of ultra-dense neutron stars called magnetars – the cinders of stars left over after a supernova.In 2014 she moved as a Professor of Physics at George Washington University.