Our Sun is enormous: 1.39 million kilometres across and 1.99 million trillion trillion kilograms. Yet it is just a lightweight compared to some of the other stars out there, giants clocking in at dozens of times the mass of the Sun. However, the truly great stars are also the most enigmatic; behemoths that measure 100–300 times the mass of our Sun. Only in the most exotic, most active star-forming regions are they found, but how are they assembled? Are they really individual stars, or are we really measuring binary or triple systems that are too close together for us to resolve? Why do they violently blow off their outer layers and what happens when they explosively die?
Stars are superb subjects for scientific study, but monster stars really are something extraordinary, which is why Professor Paul Crowther of the University of Sheffield, who led a group of astronomers that discovered possibly the most massive star in the Universe, will be speaking about these spectacular stars at European AstroFest on the afternoon of Friday 7 February.