James Webb highlights Radio-Canada's Scientist of the Year | Radio-Canada Scientists of the Year

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James Webb spotlights Radio-Canada's Scientist of the Year | Radio-Canada's Scientists of the Year Canada

Astrophysicist René Doyon wins the Radio-Canada Scientist of the Year award for his contribution to the James Webb Space Telescope, which for the past six months has revealed unpublished information about the Universe.

Astrophysicist René Doyon contributed as a Canadian principal investigator to the development of Canadian instruments on the James Webb Space Telescope, an international project led by NASA, in collaboration with the European Space Agency and the Canadian Space Agency.

In front of the fabulous images of the cosmos captured by the James Webb telescope, René Doyon's wonder is palpable: “They are absolutely breathtaking”, he says with stars in his eyes (no pun intended).

If these shots that reach us from the depths of the Universe are of unparalleled precision, it is partly thanks to him. Scientific director of the Canadian contribution to the telescope, the result of a collaboration between NASA, the European Space Agency and the Canadian Space Agency, René Doyon worked there for two decades. First to the development of a scientific device on board, called NIRISS (for Near InfraRed Imager and Slitless Spectrograph), then of a guidance camera, the Fine Guidance Sensor (FGS), essential to the proper functioning of the telescope.

When you point the telescope, a big structure, it moves in all directions. But inside there is a little mirror called the steering mirror, which is controlled by the Canadian guide camera, and which allows it to be switched in real time 16 times per second to ensure that the images are really good, very fine, explains the winner, professor of astrophysics at the 'University of Montreal.

ASC engineers install protective shroud on FGS and NIRISS in center NASA's Goddard spacecraft.

The James Webb Space Telescope was launched in December 2021 from French Guiana. It is the largest and most powerful telescope ever deployed in space. Its mirror is six times larger than that of its predecessor, Hubble.

With a much larger telescope, one can observe much fainter targets, so it is a new chapter that opens, enthuses the researcher.

Another distinction: while Hubble mainly looked at the visible light emitted in the Universe, James Webb is designed to detect wavelengths of infrared light. This is crucial for what René Doyon and his team wish to study.

Because beyond the magnificent images captured by the telescope, what fascinates the astrophysicist even more are curves. Infrared light spectra captured by telescope instruments from exoplanets.

These extrasolar planets orbit stars other than our own. Passing in front of their star, they block a small part of its light. The Canadian instrument NIRISS was designed to capture these variations in luminosity and deduce the composition of the atmosphere of these exoplanets.

In the spectrum of the different wavelengths filtered by the atmosphere of these planets, researchers can read what this atmosphere is made of. This is an extremely delicate measurement that we made with Hubble, but with much less precision, notes Mr. Doyon.

Transmission spectrum of exoplanet WASP-96 b.

Behind these curves therefore hides perhaps part of the answer to THE question posed by the scientist: are we alone in the Universe?

The ultimate goal of all this, of course, is to find out if there is life on those planets. And to do that, you have to sense their atmosphere to really know what the conditions for habitability are. We want to know the physical conditions. Is there water? Is there methane, CO2? And possibly even a biosignature, that is to say a gas that is produced by biological activity, he explains.

The researcher and his team from the Trottier Institute for Exoplanet Research, IREx, presented their first results from Webb to the scientific community last December, during a conference held at the Space Telescope Science Institute, in Baltimore. .

They analyzed data from three passes, or transits, made in front of their star by two planets in the Trappist-1 system, located nearly 40 light-years from Earth. Among the seven rocky planets of Trappist-1, some would be in a so-called habitable zone: neither too close nor too far from the star for the temperature to allow the presence of liquid water, necessary for life.

These data did not detect an atmosphere on the surface of the two planets, but the researchers hope to accumulate more data before ruling out that there is one.

The duration of the transit lasts about three quarters of an hour or an hour in the case of these planets, but we know that it is necessary to accumulate tens and tens of hours to accumulate the very, very small atmospheric signal that we are trying to detect, explains René Doyon.

We will therefore need a little patience, but the astrophysicist has plenty of it. For nearly three decades, he has been at the forefront of expanding his field of research. Since the 1990s, more than 5,000 exoplanets have been identified.

This is the second time that René Doyon has been named Radio-Canada Scientist of the Year. In 2008, he won the prize, with his colleagues David Lafrenière and Christian Marois, for the publication of the first image of exoplanets orbiting their star.

L&#x27 ;host of the show Les Années lumière, Sophie-Andrée Blondin, receives René Doyon at her microphone at 12:10 p.m., Sunday.

The report by Gaëlle Lussià-Berdou and François Perré is broadcast on the show Découverte on Sundays at 6:30 p.m. on ICI Radio-Canada Télé.