The James-Webb space telescope (Nasa) arrived at its destination, at the so-called Lagrange 2 point, on January 24. He begins to deliver images of his first target, HD 84406, one star of type G and therefore similar to the Sun, located about 258 light-years away in the constellation Ursa Major.
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[EN VIDÉO] Understand the James Webb Space Telescope mission in one minute The James Webb Space Telescope, a new flagship in space observation, will be launched on December 18 from Kourou, Guyana. After a journey of 29 days, it will reach the Lagrange point L2, in the opposite direction to the Sun. With its mirror larger than that of Hubble, of which it is considered the successor, the JWST will be able to observe galaxies, planets, nebulae and stars to learn more about the history of the Universe.
The James-Webb space telescope is expected to make it possible in particular to analyze theatmosphere of exoterres in orbit around solar-like stars hoping to find biosignatures there. One can therefore only be enthusiastic in noting that one of the steps planned for the commissioning of the instrument is proceeding perfectly, namely the obtaining of images of thestar HD 84406 located approximately 258 light-years from Solar system only.
NASA has just made public these images which are in the form of 18 luminous points, as can be seen in the photo below. They result from the accumulation of photons performed by the instrument Near Infrared Camera (NIRCam) for a total of approximately 25 hours of observation which began on February 2, 2022.
We observe 18 images of the star located in the Ursa Major constellation because the 18 elements of the mirror primary telescope are not yet finely assembled to produce a single, well-located image. The cooling of each of these elements to drop below 50 kelvins is still ongoing. The astronomers and engineers working on fully commissioning the James-Webb should take another month or so to complete the adjustments that will result in a single high quality image of HD 84406.
” The entire Webb team is delighted with the quality of the first steps in taking images and aligning the telescope. We were so happy to see light coming into NIRCam said Marcia Rieke, principal investigator of the NIRCam instrument and professor of astronomy at the University of Arizona.
Lee Feinberg, Elements Manager for the Webb Optical Telescope at Goddard Space Flight Center from NASA, explains the first steps of the mirror alignment process. To obtain a fairly accurate French translation, click on the white rectangle at the bottom right. The English subtitles should then appear. Then click on the nut to the right of the rectangle, then on “Subtitles” and finally on “Translate automatically”. Choose “French”. © James Webb Space Telescope (JWST)
The Webb Space Telescope will open its giant eye to this star in the Big Dipper
Article of Nathalie Mayer published on 05/02/2022
The James Webb Space Telescope (Nasa) arrived at its destination, at the so-called Lagrange 2 point, on January 24. And he is now almost ready to turn to his very first target. A star located in the constellation Ursa Major.
This time there it is. The four main instruments of James Webb Space Telescope (JWST, Nasa) are being powered up. And the telescope will soon be ready to turn to its very first target: a star dubbed HD 84406. A star in the Big Dipper, similar to our Sun and located some 260 light-years from Earth. With her magnitude about 6.7, it is not visible to theeye naked.
The images of this star will be taken by the infrared camera close to the JWST (NIRCam). They will not be used directly for scientific purposes. But the star makes an ideal target to help engineers line up the 18 golden segments of the James Webb Space Telescope’s more than 6-meter-wide main mirror. Their objective: to succeed in forming a clear image from the 18 blurred images that each segment should first return.
Star light, star bright…the first star Webb will see is HD 84406, a Sun-like star about 260 light years away. While it will be too bright for Webb to study once the telescope is in focus, it’s a perfect target for Webb to gather engineering data & start mirror alignment. pic.twitter.com/DleVjDZz8B
—NASA Webb Telescope (@NASAWebb) January 28, 2022
Still a lot of adjustments to make
These adjustments should continue until the end of April. And they are considered crucial. If the NIRCam were to fail in this mission, the engineers would lose any chance of aligning the JWST mirror.
According to NASA scientists, HD 84406 appears as “a perfect target to start our search for photons”. On the other hand, once the JWST is fully operational — not before next June, because it will notably still be weeks before its instruments reach their operating temperature — theUrsa Major star will become too bright to be studied by the mighty instrument.
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