R.I.P Leon Mestel (1927-2017)

Leon Mestel FRS, photographed by Lucinda Douglas-Menzies

I heard this weekend the very sad news that on Friday 15th September 2017, we lost one of our great astrophysicists. Professor Leon Mestel FRS, pictured abvove, passsed away, peacefully in his sleep, at Addenbrooke’s Hospital. He was 90 years old.

Leon Mestel was a scientist of the highest distinction. Elected a Fellow of the Royal Society in 1977, his research interests were very broad, encompassing, but not restricted to, the areas of star formation and structure, especially stellar magnetism and astrophysical magnetohydrodynamics. Among his contributions in other areas were important papers on gravitational collapse and equilibrium in the context of galaxy dynamics, of which the classic `Mestel Disk’ is just one example. He has been awarded both the Eddington Medal (1993) and the Gold Medal (2002) of the Royal Astronomical Society. He had great physical insight which was backed up with prodigious mathematical skill and an encyclopedic knowledge of astrophysics. He also had great powers of concentration and the determination to tackle the kind of extremely challenging problems that scared off lesser intellects. Leon  was an ‘old school’ theoretical astrophysicist who was held in very high regard across the astrophysics community, and he will be greatly missed.

Others more expert than me will be able to pay proper tribute to his scientific work, so I’ll restrict myself here to a few personal reminiscences.

Leon Mestel was Professor in the Astronomy Centre at the University of Sussex when I joined it to start my DPhil in 1985. We new postgraduate research research students were required to take four courses on various aspects of astronomy, and pass oral examinations on them, before being allowed to progress beyond the first year. One of these courses was a course on Stellar Structure, taught by Leon Mestel. His lectures were pretty intense – and, I have to say, not made any easier to understand by his truly terrible handwriting on the blackboard! – but I learned a huge amount from them. I still have the lecture notes I took, in fact.

I had a root around in my old files this morning and found this evidence that I once knew something about stars!

All of us found Leon very scary to start with. He was intellectually quite intimidating and seemed to be a rather fierce and irascible character. That opinion changed when, a few weeks into term, he invited us to his house in Lewes for a social evening. We were all a bit nervous on the way there, unsure of what to expect, but as it turns out Leon was a marvellously entertaining and avuncular host. He had a wicked sense of humour and a seemingly inexhaustible stream of jokes, across a spectrum from groan-worthy puns to very risqué stories, including a  liberal measure of archetypal Jewish humour.  Leon’s father was a Rabbi, actually.  That evening broke the ice and we all realised that the was one of the good guys. That he came across as grumpy sometimes was because he was concentrating very hard, but it was rather easy to make him laugh and bring that twinkle to his eye that we will all remember.

His sharp brain and very broad knowledge meant that Leon could spot bullshit at a  considerable distance and, while he often seemed to be snoozing through  our weekly seminar,  he invariably woke up at the end and asked a penetrating question. Since one of his main interests was the role of magnetic fields in astrophysics, a subject that sends many astrophysicists screaming from the room, he would often choose something about magnetism as a question. When I was there his main focus was on the fiendishly difficult problem of building a self-consistent model of the pulsar magnetosphere. He was, however, genuinely interested in all branches of astrophysics and always recognised good work when he saw it, especially from younger scientists.

During my time as a PhD student I had some problems that required me to take quite a lot of time off. Leon was extremely kind and supportive during this period, and he even bent the rules a bit to avoid putting me through the formal process of interrupting my studies. When I was back at work and just about finishing my thesis in 1988 it was Leon who came to see me in person, with a big smile on his face, and offered me a postdoctoral position at Sussex to follow my graduate studies. I nearly fell off my chair with surprise and gratitude.

After I joined the staff later in 1988, it became a bit of a ritual for us to visit the Senior Common Room (which was situated in what is now Bramber House) for lunch, followed by coffee. It turned out that Leon liked to do the Times crossword with his post-lunch coffee. He wasn’t at all averse to a collaborative effort on tricky research problems, and it was thus with crosswords too. We both preferred the Guardian puzzle, actually, but he saved that one for after work and did the Times one because the paper was provided free in the SCR. There was also a Chambers dictionary.

I left Sussex in 1990 and Leon retired in 1992. I didn’t see as much of him after that, except for the occasion when he and my former DPhil supervisor John Barrow organized a meeting in 2004 about Eddington at which I was honoured to be asked to give a talk about the 1919 eclipse expeditions. That was a very nice occasion at which Leon was in sparkling form. Thereafter I saw him occasionally at the RAS Club, but in recent years he didn’t come so often as he found it increasingly difficult to get around.

Leon Mestel was not only a great astrophysicist but also a great character.  I’m so very sorry I can’t attend his funeral (which is being held tomorrow), but I send heartfelt condolences to his family, friends and colleagues.

Rest in Peace Leon Mestel FRS (1917-2017)



8 Responses to “R.I.P Leon Mestel (1927-2017)”

  1. Sad news – Leon was a regular feature in talks and seminars when I was a DPhil student in the late 90s, and although he could seem fairly terrifying he was usually quite gentle with the DPhil students and he would wait until the room was clear before pointing out the error of our ways. He even reacted with good grace when I was a brand-new student and – not knowing who Leon was – had been tricked by one of the postdocs into asking him if he’d thought of considering the effects of magnetic fields…

    Most of all, i’ll remember him as one of a group of very senior Sussex academics (also including Bernard Pagel and Harry Kroto) who were always happy to have a cup of tea and listen to the incoherent ramblings of a confused graduate student, before sending you on your way with kind words of encouragement and a gentle nudge in the right direction. After several weeks of work, you’d then start to see what they’d picked up on in moments…

    After a week or two of thought, i’d finally start to grasp what he’d seen in moments.

  2. Sad to hear, I remember his very enthusiastic Cosmic Electrodynamics classes in the Masters, in which he kept asking us if we understood. We always nodded of course, which was not an entirely true impression to say the least! But we didn’t want to disappoint him as he was so enthusiastic!
    I saw your 30th anniversary of your second paper the other day, and it reminded me that early next month will be the 30th anniversary of the beginning of my M.Sc. year in Sussex!

  3. Simon Goodwin Says:

    As a PhD student and then postdoc at Sussex from 1993-2000 Leon was a huge influence on me (at a time when you could have coffee with Leon, Bernard Pagel, Bill McCray and Roger Taylor!) . Leon was a great mentor and gave incredibly useful advice such as ‘Never believe your own theories – the best you can hope for is to be the one who proves them wrong’. But what I remember most is his wicked sense of humour (referring to me as my wife’s ‘worst half’ whenever he saw her), and his ability to see-through and call-out bullshit whenever presented with it.

    One of the greats, and he will be missed by many.

    • “Leon, Bernard Pagel, Bill McCray and Roger Taylor”

      Bill McCrea and Roger Tayler, presumably. Roger Taylor plays in a band with another astronomer, named Brian.

      Alas, all members of that august quadrumvirate are now dead. Of them, I knew only Bernard, also a good example of a good scientist and friendly chap.

      • Yes, it’s sad that they’re all gone.

      • Indeed, coffee on the Bridge was quite a thing. In my M.Sc. year of 1987-88 there was Mestel, Tayler, Smith and Barrow (and Coles of course). Pagel was based in Herstmonceux I think and McCrea didn’t seem to come to coffee. We’d only see him at the lunchtime seminars, and for a few weeks we wondered who was this friendly man who came to chat to the new M.Sc. students but didn’t seem to be a member of staff, until someone explained to us who he was. I mentioned him just recently to my Extragalactic Astrophysics and Cosmology undergrad students, while going through that Newtonian derivation.
        As a cricket fan my most memorable moment at coffee was when Roger Tayler said he’d attended the Test Match at the Oval in 1938 when England had scored 903-7dec y Australia and Len Hutton scored a then record 364 runs.

    • Milne and McCrea wrote a famous paper on “Newtonian cosmology”. At least, that is what everyone says; I’ve never heard it any other way. However, the order of names on the paper is the opposite, i.e. McCrea and Milne. How and why did this reversal come about?

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