“Roger Griffin transformed the way that stellar radial velocities were measured and his work is fundamental to the way black holes and extrasolar planets are evidenced to this day"

The award-winning astronomer Professor Roger Griffin, who spent his career studying starlight, has died. 

Professor Roger Francis Griffin, BA, PhD, ScD, Fellow of St John’s College 1962-1965 and again from 1972, and Emeritus Professor of Observational Astronomy at the University of Cambridge, died on 12 February 2021, aged 85.

The scientist is credited with developing the method that is now used for measuring black holes and is used to provide evidence for extrasolar planets – planets outside the Solar System. Professor Griffin is survived by his two children, Rupert and Richard.

Heather Hancock, Master of St John’s College, said: “Roger Griffin transformed the way that stellar radial velocities were measured and his work is fundamental to the way black holes and extrasolar planets are evidenced to this day. A keen marathon runner, he was known by many in the running club by his nickname Yogi, rather than as the distinguished Professor that he was. In usual times, he was a familiar sight at St John’s and he will be greatly missed by the College community. Our thoughts and best wishes are with his family.”

Born on 23 August 1935, Roger Griffin arrived in Cambridge from his family home in Surrey in 1954 to study Natural Sciences as an undergraduate at St John’s. He continued to postgraduate study and pursued a PhD in Astronomy.

He was one of the four world-leading astronomers hailed as the real life 'Big Bang Theory reunion' when they starred in a BBC documentary called Britain's Star Men: Heroes of Astronomy. The programme celebrated 50 years of friendship during a road trip to revisit some of the world's greatest observatories. Reviewers were 'charmed' by their stories and said the world-leading astronomers 'brought the universe down to earth'. 

Roger Griffin joined the Fellowship as a Title A Research Fellow in 1962 where he was promptly given the nickname Yogi Bear by his peers. Many other Research Fellows at St John’s in the 1960s also adopted nicknames including the word bear in his honour. To many people in Cambridge, he became known as Yogi. In 1971 when he had his first child with his then wife, Rita, whose own nickname was Cindy after Yogi Bear’s girlfriend, they named their son after a very famous bear.

In an email in 2014, Professor Griffin explained: “When we had a boy offspring he obviously had to be a bear with a name beginning with R to keep it in the family so he could not help being Rupert!”

Professor Griffin spent his career working on stellar spectroscopy – the study of the spectra of starlight. He worked in Cambridge for more than six decades, bar one year when he had a post-doctorate position at the Mount Wilson and Palomar Observatories, Carnegie Institution of Washington. He was the Assistant Director of Research in Astronomy at the University of Cambridge for nine years before he was promoted to a Readership of Observational Astronomy and later a Professorship.

His interest focused on the measurement of stellar radial velocities. In a 2019 article about his work, he said: “Such velocities had always been determined, since photography became useful in the late nineteenth century, by exposing a photographic plate to the star spectrum and also to the spectrum of a laboratory emission source through adjacent parts of the length of the same spectrographic entrance slit. After processing the plate one then had to measure the stellar and laboratory spectra line-by-line in a high-class measuring machine (travelling microscope).”

His love of running led him to compete in the London Marathon 10 times and when he was 69, he climbed Mount Kilimanjaro with son Rupert

In the 1960s, during his time as a Research Fellow at St John’s, he developed a new method using a 36-inch reflecting telescope, where the stellar spectrum was cross-correlated in real time with a mask that looks like a high-contrast photographic negative of a typical star spectrum. But the new method was widely ignored for many years despite Griffin describing it as ‘far better in sensitivity, precision and ease of use’ than the old method that was widely used at the time'.

Professor Griffin said: “For 10 years I made more and better measurements here than the rest of the astronomers in the world put together. Eventually I decided that an advertising campaign was called for.”

As one of the Editors of the journal The Observatory, he decided to publish a series of papers giving the orbits of binary stars using his new photoelectric method. So he could ‘flourish the method before the astronomical public in paper after paper’. He found resistance to the method eventually collapsed and ‘it soon became the case that nobody would dream of measuring velocities in any other way than by cross-correlation’.

With some disgruntlement, Professor Griffin observed: “Almost all the evidence for such diverse things as black holes and extra-solar planets is derived by the method. If I got a citation every time anyone measured anything spectroscopically by cross-correlation my citation record would increase by hundreds a week! But nobody pays me that compliment.”

More than 200 papers have now been published on the measurement of stellar radial velocities in The Observatory and in 1991 Professor Griffin was honoured at an International Workshop in Switzerland to celebrate the publication of paper number 100. In 2008, the publication of paper 200 was celebrated at a meeting organised by the Royal Astronomical Society. In a career of scholarships and prizes, in 1980 he was awarded the Jackson-Gwilt Medal and Gift again by the Royal Astronomical Society.

Other notable academic achievements include making an instrument with his collaborator James Gunn, for the 200-inch reflector which was then the largest telescope in the world at the Palomar Observatory, and inventing the Griffin radial velocity speedometer in the 1970s.

Professor Griffin was a keen member of the Cambridge University Hare and Hounds cross-country running club where he was also known as ‘Yogi’ rather than as a distinguished Professor. His love of running led him to compete in the London Marathon 11 times. In 2003, he ran the fastest of anyone his age or older, and completed the 26.2 miles run in three hours and 30 minutes. Two years later, when he was 69, he climbed Mount Kilimanjaro in Africa with his son Rupert. The pair camped overnight in the summit crater at 19,000 feet. 

The Reverend Dr Andrew Macintosh, a Fellow of St John's, paid tribute to Professor Griffin: "Roger Griffin and I go back some 60 years. We were both ‘born’ Johnians and, though we coincided for a year as undergraduates, I did not know him well then. When I returned as chaplain in the late 60s, Roger, now a Fellow, was a prominent member of the Chapel squad and, under the nickname Yogi, successfully extended warm elder-brother support to many undergraduates.

"His perception at work and at play was always focused, enhanced in the former sphere by the invention of cunning devices for measuring stars, and in the latter by visceral loathing of anything that was not crafted by Cranmer or Coverdale.   His commitment to distance running became legendary and his oft participation as an ancient in the London marathon was much admired. His devotion to the College and to his friends was little short of fanatical and for long he wondered how many cubic feet of cake could be inserted into the Chapel."

The College flag is flying at half-mast in his honour.

Published: 17/2/21

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