Gilles Fontaine (1948 – November 1, 2019) was a professor of astrophysics at the

Université de Montréal The Université de Montréal (UdeM; ; translates to University of Montreal) is a French-language public research university in Montreal, Quebec, Canada. The university's main campus is located in the Côte-des-Neiges neighborhood of Côte-de ...

Quebec, Canada Quebec ( ; )According to the Canadian government, ''Québec'' (with the acute accent) is the official name in Canadian French and ''Quebec'' (without the accent) is the province's official name in Canadian English is one of the thirteen p ...

. Fontaine's research interests included theoretical and observational studies of

white dwarf A white dwarf is a stellar core remnant composed mostly of electron-degenerate matter. A white dwarf is very dense: its mass is comparable to the Sun's, while its volume is comparable to the Earth's. A white dwarf's faint luminosity comes fro ...

s, sub-dwarf stars and

astroseismology Asteroseismology or astroseismology is the study of oscillations in stars. Stars have many resonant modes and frequencies, and the path of sound waves passing through a star depends on the speed of sound, which in turn depends on local temperature ...

(the interpretation of variations in brightness of certain pulsating or vibrating stars to understand their interior structure). In particular, he found that white dwarfs can serve as test benches for the

equation of state In physics, chemistry, and thermodynamics, an equation of state is a thermodynamic equation relating state variables, which describe the state of matter under a given set of physical conditions, such as pressure, volume, temperature, or internal ...

, the coefficient of transport, and the

phase transition In chemistry, thermodynamics, and other related fields, a phase transition (or phase change) is the physical process of transition between one state of a medium and another. Commonly the term is used to refer to changes among the basic states of ...

between solid and liquid states at very high densities.

Early life and education

Gilles Fontaine was born in 1948 in

Lévis, Quebec Lévis () is a city in eastern Quebec, Canada, located on the south shore of the St. Lawrence River, opposite Quebec City. A ferry links Old Quebec with Old Lévis, and two bridges, the Quebec and the Pierre-Laporte, connect western Lévis with ...

. He obtained a Bachelor of Science degree from

Université Laval Université Laval is a public research university in Quebec City, Quebec, Canada. The university was founded by royal charter issued by Queen Victoria in 1852, with roots in the founding of the Séminaire de Québec in 1663 by François de Montmo ...

in 1969. He arrived at the

University of Rochester The University of Rochester (U of R, UR, or U of Rochester) is a private research university in Rochester, New York. The university grants undergraduate and graduate degrees, including doctoral and professional degrees. The University of Roc ...

in the fall of that year to begin his graduate work, initially hoping to study quantum optics. However, he ended up following his interest in astronomy to work with Hugh M. Van Horn on modeling

convection Convection is single or multiphase fluid flow that occurs spontaneously due to the combined effects of material property heterogeneity and body forces on a fluid, most commonly density and gravity (see buoyancy). When the cause of the convec ...

in the surface layers of white dwarfs.

Career

After receiving his PhD in 1974, he completed a postdoctoral fellowship at

University of Western Ontario The University of Western Ontario (UWO), also known as Western University or Western, is a Public university, public research university in London, Ontario, London, Ontario, Canada. The main campus is located on of land, surrounded by resident ...

where he worked with John Landstreet, gaining experience with observational astronomy. In 1977 he became an assistant professor at the Université de Montréal. He was promoted to associate professor in 1980 and full professor 1986. In 1981, expanding upon his PhD research in white dwarfs, Fontaine founded a research group specializing in white dwarf asteroseismology with his colleague François Wesemael. This research group received international acclaim for its wide-ranging contributions to our understanding of white dwarfs. Three of Fontaine's PhD students, would go on to win the

Canadian Astronomical Society The Canadian Astronomical Society (CASCA; french: link=yes, La Société Canadienne d'Astronomie) is a Canadian society of professional astronomers, founded in 1971 and incorporated in 1983. The society is devoted to the promotion and advanceme ...

Plaskett medal, awarded for the most outstanding doctoral thesis in astronomy at a Canadian university. In 1982, the group made headlines by predicting the existence of a new type of pulsating star, a DB white dwarf, which was later confirmed by telescope observations. This was the first time that the existence of a variable star was predicted by mathematical models first, rather than being discovered first through observations. In 1987, Fontaine along with his collaborators, attempted to determine the

age of the Universe In physical cosmology, the age of the universe is the time elapsed since the Big Bang. Astronomers have derived two different measurements of the age of the universe: a measurement based on direct observations of an early state of the universe, ...

using the amount of time it takes for white dwarfs to cool. Comparing observations to numerical simulations, the found that the Universe is between 10 billion and 300 million years old. In 1990, his group published the first results from the

Whole Earth Telescope The Whole Earth Telescope is an international network of astronomers that collaborate to study variable stars. The distribution of the observatories in longitude allow the selected targets to be continuously monitored despite the rotation of the ...

, a network of telescopes around the world located at different longitudes that could collectively provide continuous observations of pulsating white dwarfs. In 1996, the asteroseismology group at the Université de Montréal once again predicted a new type of variable star, a B-type white subdwarf, which was confirmed by observations by the

South African Astronomical Observatory South African Astronomical Observatory (SAAO) is the national centre for optical and infrared astronomy in South Africa. It was established in 1972. The observatory is run by the National Research Foundation of South Africa. The facility's funct ...

in 1997. In 1992, he became a fellow of the

Royal Society of Canada The Royal Society of Canada (RSC; french: Société royale du Canada, SRC), also known as the Academies of Arts, Humanities and Sciences of Canada (French: ''Académies des arts, des lettres et des sciences du Canada''), is the senior national, bil ...

and in 2016 he was awarded the

Canadian Association of Physicists Canadian Association of Physicists (CAP), or in French Association canadienne des physiciens et physiciennes (ACP) is a Canadian professional society that focuses on creating awareness among Canadians and Canadian legislators of physics issues, spo ...

Medal for Lifetime Achievement in Physics "for his pioneering, world-renowned work in theoretical and observational studies of white dwarf stars." Over his career, he published more than 200 scientific articles. He was a member of the Institute for Research on Exoplanets (iRex) and the Centre de recherche en astrophysique du Québec (CRAQ). Fontaine died November 2, 2019, in Montreal, Quebec.

Awards

* 1986 - E.W.R. Steacie Memorial Research Fellowship * 1987 - E.W.R. Steacie Prize * 1989 - Urgel-Archambault award * 1990 -

Killam Killam is a surname. Notable people with the surname include: * Albert Clements Killam (1849–1908), Canadian lawyer * Amasa Emerson Killam (1834–1922), Canadian politician * Dorothy J. Killam (1900–1965), Canadian philanthropist * Eva Ki ...

Fellowship * 1992 - Fellow of the

* 1999 -

Prix Marie-Victorin The Prix Marie-Victorin is an award by the Government of Quebec that is part of the Prix du Québec, which "goes to researchers in the pure and applied sciences whose work lies in fields outside biomedicine. These fields include the natural and ph ...

* 2000 - Carlyle S. Beals Prize *2001 - Tier 1

Canada Research Chair Canada Research Chair (CRC) is a title given to certain Canadian university research professors by the Canada Research Chairs Program. Program goals The Canada Research Chair program was established in 2000 as a part of the Government of Canada ...

in Stellar Astrophysics * 2012 - Top 10 Discoveries of the year 2012 by Québec Science * 2016 -

(CAP) Medal for Lifetime Achievement in Physics *2019 -

Asteroid An asteroid is a minor planet of the inner Solar System. Sizes and shapes of asteroids vary significantly, ranging from 1-meter rocks to a dwarf planet almost 1000 km in diameter; they are rocky, metallic or icy bodies with no atmosphere. ...

400811 Gillesfontaine was named in his honour.

References

External links

Whole Earth Telescope
{{DEFAULTSORT:Fontaine, Gilles Canadian astrophysicists 1948 births 2019 deaths Fellows of the Royal Society of Canada People from Lévis, Quebec 20th-century Canadian astronomers Academic staff of the Université de Montréal Université Laval alumni University of Rochester alumni