Gerard F. Gilmore

Gilmore was elected a Fellow of the Royal Society (FRS) in 2013. His nomination reads:

Gilmore was awarded a Master of Arts degree and a Doctor of Science (ScD) degree from Clare Hall, Cambridge in 2002.

In 1994 he was appointed to a readership in astrophysics in the University of Cambridge. In 2000 he was promoted to professor of experimental philosophy.

Gerry Gilmore leads efforts to understand the structure and origin of our Galaxy. He led a revival of star-count analysis that first showed that the Galaxy possesses a "thick" disc, and helped to show that the thick disc formed early in the Galaxy's life. Our current understanding of how the masses of stars are distributed at birth was produced by Gilmore's team. In the early 1990s with a student he obtained the still standard estimate of the mass surface density associated with the discs. This study set the pattern of future work. He pioneered the use of spectral surveys to unravel the Galaxy's history through its chemistry and established that stars in the halo of the Galaxy are chemically distinct from stars in the Galaxy's satellites, even though much of the halo must consist of stars stripped from satellites. In 1994 with a student he discovered the Galaxy's most important satellite after the Magellanic Clouds. As its leading UK proponent, Gilmore played a big role in selection of ESA's revolutionary Gaia mission. He is the driving force behind the ESO-Gaia survey, which has over 250 co-investigators and will obtain spectra designed to complement data from Gaia.

Gilmore moved to the Institute of Astronomy of the University of Cambridge in 1984 on being awarded an advanced research fellowship by the Science and Engineering Research Council. He used observations of spectra of stars to study the structure of the Galaxy, particularly by measuring their radial velocities. Working with Konrad Kuijken, he used spectra of faint stars in the region around the South Galactic Pole obtained with the Anglo-Australian Telescope to measure the stars' radial velocities, and consequently to determine the surface mass density of the Galactic disc. They showed that there was little or no dark matter within the disc other than that part of the Galactic dark matter halo that extends through the disc. Consequently, dark matter within the Galaxy does not concentrate within the disc.

Gilmore remained at the University of Canterbury as a postgraduate research student. He used the 0.61-metre telescope at Mount John University Observatory to monitor changes in the brightnesses of quasars in the southern hemisphere of the sky. He measured the magnitudes of about 130 quasars from a large number of photographic plates. He found the results were best explained by the infall of gas on to supermassive black holes. This research led to the award of a PhD degree in 1979.

Gerry Gilmore worked as a research fellow at the Royal Observatory, Edinburgh, Scotland, between 1979 and 1984. He used the expertise gained during his PhD to measure brightnesses and numbers of stars from photographic sky surveys. Working with Neil Reid with data from the United Kingdom Schmidt Telescope, he found an excess of faint stars compared to standard models of the Galaxy that represented the distribution of stars as two simple components. Gilmore and Reid argued the observed numbers of stars implied the existence of an additional component they called the thick disc that exists alongside the main Galactic disc and the stellar halo.

Gilmore was educated at St Bede's College, Christchurch and the University of Canterbury, where he was awarded a Bachelor of Science degree in 1973.

Gerard Francis Gilmore FRS FRAS FInstP (born 7 November 1951) is Professor of Experimental Philosophy, in the Institute of Astronomy, at the University of Cambridge. His research has centred on studying stars in the Galaxy to understand its structure and evolutionary history.