At the beginning of the 3rd century civil war raged in Britain as the Roman emperor Septimius Severus sought to quell unrest in the north. But unknown to the fighting cohorts and Caledonian tribes, high above their heads two stars were coming together in a huge cataclysmic explosion. Now 1800 years later the light from that collision will finally arrive on Earth creating a new star in the night sky - dubbed the ‘Boom Star - in an incredibly rare event which is usually only spotted through telescopes. Before their meeting the two stars were too dim to be seen...