Paul Murdin - Five way interview

Paul Murdin in his own words: The crucial and overriding incident that defined my life irrevocably was catching polio at the age of 7 years.  That made it difficult to walk. It made me sedentary and an avid reader – a swot. I studied because I liked to, and that made it possible for me to go to university via a scholarship to Oxford. I was able to develop this into a job as an astronomer at the Royal Greenwich Observatory (RGO).  

In the late 1960s I became interested in identifying the stars newly discovered as responsible for emitting X-rays. The X-rays are a flag that a star is waving at us saying 'Look at me!  I’m interesting! Working with Louise Webster, I found in 1971 that one such star, Cygnus X-1, was a black hole. I think that qualifies as interesting!  I went on to work at the Anglo-Australian Observatory but soon returned to the RGO to work setting up the UK telescopes on La Palma. 

In the later part of my life, I became a scientific administrator at the RGO, the Royal Observatory Edinburgh, and then at the Research Council then responsible for UK space science. For the past twenty-five years I have been writing popular astronomy books in my spare time. I was awarded an OBE in 1988.

Paul's new book is Exoplanets.

Why Astronomy?

On holiday at the seaside, aged about 11, I used 6 old pence from my pocket money to buy a little book on astronomy from a box of odd items on a shelf outside a secondhand book shop in Arundel. It was a wartime economy printing with pinkish covers. It featured constellation charts. For the rest of the holiday at dusk I lay down on my back on the beach with a torch, holding the book open above my head at the right chart to identify what was in front of me. I was enthralled by the mythology of the constellation figures and attracted by the mysterious names of the stars. I was thrilled when, later that week, Perseid meteors flashed through the sky, building to their maximum rate.  

This firsthand experience started my interest, and lasted with me while I worked through school, studying science and maths and going on to university. A year or so later, an eight-week course at the Royal Greenwich Observatory in the summer vacation confirmed my deep interest in astronomy, through the project I was given to measure the positions of stars on glass photographs of the Omega Centauri globular cluster taken over twenty years. It staggered me that you could use this data to say which stars really belonged to the cluster (because they were moving together through the stars that lay by chance in the same direction, which moved in all directions at random), and, even more surprisingly, plot its orbit around the Galaxy. It was rosette shaped – who’d have guessed?  

Why this book?

Attending seminars at the Institute of Astronomy at Cambridge over the past several years, I became aware of the extraordinary variety of planets in orbit around other stars beyond the Sun. I started to try to make sense of the different sorts, and relate the astronomical circumstances of each to what was known of its surface conditions. As more and more of it began to make sense I realised that this was the first time in history we could know, with some scientific basis, about the surfaces of other planets and that this could make an interesting book, or at least one that I would like to write.

What is happening at the moment?

There are a number of powerful instruments coming into play in the next few years specifically designed to discover exoplanets and investigate their properties. We need them to scope out the range of planets that exists beyond the few sorts of planets in our solar system, and gather large samples of each kind, the better to be able to search for the rare kinds caught as they change from one kind to another. We are currently in the same position now as Hertzsprung and Russell were as they gathered data for the HR diagram of stars.

What excites you at the moment?

Obviously the prospect of finding planets like Earth, or slightly different, so we can see the factors that are crucial for a terrestrial life. But I think it is less a question of the next single discovery and more a question of doing the hard work to understand what is happening in general.

Image © Stephen Armishaw

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