Wolstencroft conducted research ranging from the interplanetary and interstellar medium, space and high-energy astrophysics, space biology, and to galaxies and cosmology.
Wolstencroft passed away peacefully on February 14, 2017, in Edinburgh at the age of 80.
Ramon David Wolstencroft, a specialist observer and instrument maker, was active in a broad range of areas, from the nature of the interplanetary and interstellar medium, especially the Zodiacal Light and the Solar Wind, to space and high-energy astrophysics, space biology and to galaxies and cosmology. He was a student of Donald Eustace Blackwell at the University of Cambridge and earned a Ph.D. with a thesis on ”The Interplanetary Gas” in 1962.
Born on July 25,1936 to Albert and Edith (Watmough) Wolstencroft in Chelmsford, Essex, England, Wolstencroft served in the military before entering college, specializing in radar electronics. He obtained his Bachelor of Science from University College, London in 1959, and then entered Cambridge. Working under Blackwell, he built a multi-bandpass polarimeter with a rotating waveplate device, and with Blackwell travelled to La Paz, Bolivia, to study the polarization and brightness of the zodiacal light in five colors.
After his thesis he had several job offers due to his expertise in electronics and decided to work with Joseph W. Chamberlain who was then moving to Kitt Peak National Observatory to become associate director of a new Space Division. Working as a junior astronomer on a Fulbright scholarship under Chamberlain from 1962 to 1965, he designed and flew an array of photometers on an Aerobee 150 sounding rocket in September 1964 to continue studying the Zodiacal Light, confirming that the gegenschein was immersed in a negatively polarized region.
At the end of his Fulbright, Wolstencroft had to return home. He had alerted Blackwell and others that he would be looking for a job. He had also recently married Susan Elizabeth Couling, so the two decided to take “the slow route” back home from Tucson to Los Angeles, Hawaii, Japan, the Philippines, and India. During their 50-day journey in 1965 Wolstencroft received a number of job offers; from the British Science Research Council and then from the University of Edinburgh, which he accepted. During their stop in Hawaii, Wolstencroft became acquainted with Jerry L. Weinberg’s zodiacal light program on Haleakela and sought ways to maintain contact while taking up a variety of posts at Edinburgh, including senior science officer at the Royal Observatory, Edinburgh, then lecturer at the University. He remained connected to Edinburgh while he accepted an offer to be on the faculty of the University of Hawaii’s Institute of Astronomy, which he held from 1968 until 1976 before returning to Edinburgh and the Royal Observatory, where he spent the remainder of his career.
Wolstencroft was captivated by the promise of Hawaii for astronomy. He was encouraged by John Jeffries’ efforts to improve and modernize the instrumentation at Haleakela, recalling that:
“It quickly became clear that it was a brilliant site. I do remember the Canadians, the Canada-France people that came, they’d heard on the grapevine that this is the place to be. They came in 1971. They had plans to do a very complex site survey. What they found was that there were six weeks of absolute perfect weather. (Wolstencroft 2015; )”
So in in the 1960s and 1970s Wolstencroft collaborated with University of Hawaii staff and other visiting astronomers on a wide variety of projects. Given his expertise in polarization studies, Wolstencroft accepted an invitation to team up with James Kemp from the University of Oregon, on sabbatical in Hawaii in 1970, who had developed a piezo-optical birefringence modulator, more commonly called a “photoelastic modulator polarimeter,” to detect circular polarization which revealed magnetic field structures in a wide range of celestial objects. Kemp had just discovered the first magnetic white dwarf and with Wolstencroft used the University of Hawaii’s 88-inch telescope on Mauna Kea to refine and extend this work. Between 1970 and 1974 they published some 21 papers exploring the planets, quasars, supernovae, and a wide range of variable stars (Kemp & Wolstencroft, 1972; ).
Throughout the rest of his career, Wolstencroft continued to collaborate with a wide range of astronomers from many countries, exploring and refining techniques to measure polarization and use it to explore many questions, from detecting extra-solar planets to measuring the reflection of sunlight from the earth’s waters in search of biological markers for photosynthesis as a step toward finding life on earth-like planets. He rose in the ranks at Edinburgh to become deputy director in 1992, retaining that affiliation throughout the turbulent period in the late 1990s when parts of the Royal Observatory in England were absorbed by Edinburgh, partly due to severe cost-cutting to maintain Britain’s role in the establishment of the Gemini observatories.
Wolstencroft remained active in several Commissions of the IAU until his death. His last publication of some 200 papers noted by the ADS was in 2007. Father to David and Mark, and grandfather to Leiomi and Vida, he passed peacefully on February 14, 2017, in Edinburgh.
David DeVorkin is Emeritus Senior Curator, National Air and Space Museum. His current research is centered on the life of George R. Carruthers.
See also Wolstencroft’s AstroGen entry.