ESA’s space telescope Gaia, which maps the Milky Way, completes its active phase of scanning the sky on 15 January. Over the past decade, Gaia has made more than three trillion observations of about two billion stars and other cosmic objects. ‘Gaia is already the discovery machine of the decade,’ Leiden…

They hurtle along at over a thousand kilometres per second: the fastest stars in the Milky Way. PhD candidate Fraser Evans conducted research into these elusive hypervelocity stars and discovered that they have a lot to teach us, about black holes and supernovae, for example.