Binaries: Keys to the Universe

Many stars in our Galaxy have at least one companion star, so they orbit each other as part of a binary star system. In many cases, the two stars will interact at some point during their lives, with many different outcomes. I will describe some of the weirder ways binaries can evolve, including their role in several key recent astronomical discoveries: the discovery of the accelerating expansion of the Universe, and the discovery of gravitational waves.

Dr Helen Johnston obtained her PhD at the California Institute of  Technology. Subsequently she held appointments in The Netherlands, at the Anglo-Australian Observatory and at the University of Sydney. Her research interests are the study of neutron stars and black holes, especially those systems called X-ray binaries where the neutron star or black hole is accreting matter from a companion star.