First galaxies, distant stars, exoplanets… the program for the first year of observation has been determined in advance by a committee of experts, and has been for more than a year now.
Anyone can, in theory, use this telescope for their research – provided they know what to observe and have their proposal selected.
Among the lucky ones, Olivia Lim, doctoral student at the University of Montreal, who is only 25 years old.
I’m lucky enough to use this telescope when I wasn’t even born when people started talking about itshe told AFP.
Its goal: to observe planets revolving around a star called Trappist-1. The system has seven planets in all, similar in size to Earth. They are so close to each other that from the surface of one, you could see the others appearing clearly in the sky.
Trappist-1 is uniqueexplains the young woman.
All the conditions, or almost all, are favorable there for the search for life outside our solar system.
They are indeed rocky (and not gaseous) planets. In addition, three are in the so-called area
livablethat is, neither too close nor too far from their star, offering adequate temperatures for liquid water to exist on their surface.
Other advantages: they are located
only 39 light years. And, above all, we can see them passing in front of their star from our point of view (we say that they transit their star).
This is what makes it possible to study them, by observing the drop in luminosity that their passage in front of the star produces. Several of these transits should be observed as early as this month.
It’s not yet known if these planets have an atmosphere, but that’s what Olivia Lim is looking to find out. If so, light passing through the atmosphere will be
filtered by the molecules it contains.
The jackpot would be to detect the presence of water vapor, CO2 or ozone, specifically sought.
Trappist-1 is such a prime target that several other science teams have also been granted time to observe them.
Finding traces of life there, if they exist, will still take time., according to Olivia Lim. But
everything we’re doing this year are really important steps to get to that ultimate goalunderlines the researcher.
Besides exoplanets, one of James Webb’s other great promises is the exploration of the early ages of the Universe.
How? Because the farther one looks, the longer one sees. Sunlight, for example, takes eight minutes to reach us, so we see it as it was eight minutes ago. Thus, by looking as far as possible, one can perceive the light as emitted billions of years ago.
Astronomers have so far succeeded in going back 97% of the time to the big bang, which occurred 13.8 billion years ago.
But the most distant galaxies appeared for the moment only in the form of
tiny red spotsexplained to AFP Dan Coe, astronomer at the Space Telescope Science Instituteresponsible for James Webb’s operations in Baltimore, near Washington.
The researcher has two upcoming observation programs: the first targeting one of the most distant galaxies known, MACS0647-JD, discovered in 2013, and the second focusing on Earendel, the most distant star ever detected, since this year. only.
With James Webb, we’re finally going to be able to see inside these galaxies, see what they’re made of, both in image and spectroscopy, it’s going to be amazinghe assured.
Spectroscopy makes it possible, via the analysis of the light captured, to determine the chemical properties of a distant object.
While recent galaxies may be elliptical or spiral, older ones were more
irregularnotes Dan Coe.
And we don’t yet know what the very first stars look like, which probably began to form a hundred million years after the big bang.
According to the theory, these early so-called population III stars were much more massive than our Sun, and made entirely of hydrogen and helium. Their supernova explosion then contributed to enrich the interstellar medium, until the formation of the planets and stars of today.
Some doubt that it is possible to see these stars. But that won’t stop astronomers from continuing to try.