James-Webb Telescope: his summer album

Harvests from the skies continue to be bountiful for the James-Webb Space Telescope (JWST). The result of a collaboration between the American, European and Canadian space agencies, the successor to the Hubble telescope has been in orbit 1.5 million kilometers from Earth since the end of January. After the fireworks of July 11 and 12 showing his first extraordinarily detailed images of a nebula (the Carina), colliding galaxies (Stephan’s Quintet), a portion of sky studded with galaxies, a planetary nebula (known as the “austral ring”) and a survey of the atmospheric composition of an exoplanet, the summer harvests are just as good.

” It’s extraordinary. Expected performance is exceeded. The quality of the data lives up to the promises. We are living a dream! »enthuses Hervé Dole, professor at the Institute of Space Astrophysics, at the University of Paris-Saclay. “ The instrument is amazing. It can image Jupiter as well as distant galaxies whose brightness is one to ten million times weaker.believes Olivier Berné, CNRS researcher at the Institute for Research in Astrophysics and Planetology in Toulouse.

Every day, the JWST’s 6.5-meter mirror points to sources as varied as very distant galaxies or stars that appeared in the first billion years of the Universe, closer clusters of galaxies, supernovae, exoplanets, planets of our solar system, comets or asteroids… “We jumped on this data”proclaims Hervé Dole, who has already submitted an article on the hypothetical presence of the most distant proto-cluster of galaxies ever spotted, 600 million years after the Big Bang. A proto-cluster is a geographical grouping of galaxies, here less than ten, which will become a true cluster millions of years later, with a lot of hot gas within it. “I had never written an article in two weeks. We launched into a hotel lobby with a colleague looking at the deep sky image, a few days after it was broadcast on July 11. We expected to have the results quickly, but this is almost immediate! »says the astrophysicist.

But it was one of his colleagues at the ENS de Lyon, Johan Richard, with other American, English and even Swiss researchers, who drew the fastest. As of July 14, at 7:55 p.m. Paris time, less than 3 days after the revelation of the first image, it puts a preprint online on the specialized site arXiv.org to characterize the galaxy which distorts the image of the sky and acts as a magnifying glass vis-à-vis distant galaxies located beyond. “We even started the analysis with the naked eye from the image provided. Then we used the more raw data., recalls Johan Richard, who has since co-signed three other preprints. Thirteen seconds later, another team respondson the same subject…

You have 78.75% of this article left to read. The following is for subscribers only.