Paul Geoffrey Murdin OBE FRAS (born 5 January 1942) is a British astronomer. He identified the first clear candidate for a black hole, Cygnus X-1, with his colleague Louise Webster. He studied Mathematics and Physics at the universities of Oxford and Rochester. In 1962, he took an eight-week summer residential course supporting researchers at the Royal Greenwich Observatory in Herstmonceux and at the end was offered a post by the Astronomer Royal, Richard Woolley. He left to study a PhD at Rochester and returned to the RGO in 1970 as a research fellow. During his three-year contract there, he wondered what he could contribute to find out about the provenance of powerful cosmic x-ray sources that had recently been detected, particularly Cygnus X-1. After he had made unsuccessful searches fo