The great discovery of James Webb

sOr, for the first time in history, researchers have been able to detect light coming from an exoplanet close to Earth, rocky and relatively benign. In this case, in a small range of wavelengths corresponding to their thermal emission, in other words the heat they emit into space.

This feat is the work of an international team of six scientists, including three French from CEA (Commission for Atomic Energy and Alternative Energies). To achieve this, they used The extraordinary capabilities of the James Webb Space Telescope And in particular, the MIRI (medium infrared) device, designed largely at CEA in Paris– Saclay.

“We used a technique called secondary eclipse photometry. This consists of observing the star when it is not in transit in front of its star, the night side towards the Earth, but on its side, showing us its day side as closely as possible before it disappears behind the star,” he explains. a point Elsa Ducrot, an astrophysicist at CEA and co-author of the new study published in the popular journal nature. “This way, we can distinguish between when we receive light from the star with light from the daytime side of the planet, and when we receive only that from the star, with the planet hidden behind it,” she says.

The light curve shows this change in brightness […] read more