The Royal Astronomical Society (RAS) is saddened to hear of the passing of Dr Allan Chapman, who has died aged 79.
Described as "extraordinarily erudite" and an "indomitable spirit", Dr Chapman was a historian with a particular interest in scientific biography and astronomy.
He regularly appeared on the long-running BBC programme The Sky at Night and fronted several documentaries as a television presenter. They included Channel 4's Gods in the Sky, covering astronomical religion in early civilisations, and Great Scientists, presenting the lives of five of the greatest thinkers.
Dr Chapman also took part in the TV quiz show University Challenge: The Professionals as part of the RAS team, broadcast in 2006.
He wrote several books and lectured extensively in the history of science in England and abroad. In January 1994, he gave the Royal Society's triennial Wilkins Lecture in the History of Science, on Edmond Halley.
Dr Chapman was a Fellow of the RAS and in 2015 received the Society's Jackson-Gwilt Medal for his work on the history of astronomy.
President of the RAS, Professor Mike Lockwood, said Dr Chapman was "a truly delightful and extraordinarily erudite man".
He added: "When I was a young scientist, RAS highlights meetings were called 'ordinary meetings' – but they were truly extraordinary if Allan Chapman was speaking.
"He would stand in the middle of the stage, no notes, no microphone, no lectern, no viewfoils, no PowerPoint and tell us about the lives of famous astronomers in fascinating detail.
"Delivered with perfect clarity and perfect prose and never with any 'repetition, hesitation or deviation': those talks must have lasted the best part of an hour but they did indeed seem to fly by in 'just a minute'."
Dr Chapman was born in Manchester in 1946. He graduated from the University of Lancaster in 1972, before embarking on postgraduate work at Wadham College, Oxford and later teaching the history of science in the Faculty of Modern History, Oxford.
He is a founder member and president of the Society for the History of Astronomy and in 2004 received an honorary doctorate from the University of Central Lancashire.
Dr Chapman also regularly contributed to the magazine Astronomy Now, which will be publishing his final article on the great observatories of North America alongside an appreciation of his life and work in March's issue.
Dr Stuart Clark, Editor of Astronomy Now and a Fellow of the RAS, said: "This is a devastating loss to the UK astronomical community.
"Allan was an indomitable spirit and one of the foremost historians of astronomy who has ever lived. While UK astronomy will never be the same again, we are all infinitely richer for the life's work that he leaves behind."
The RAS offers its sincere condolences to Dr Chapman’s family, friends, and all those who had the privilege to know and work with him.