James Webb: a first and sublime star image taken by the 6.5m diameter mirror

This time, the 18 mirror segments of the James Webb Space Telescope (JWST) are (nearly) perfectly aligned, meaning the telescope can already capture images of the universe as if it had a single 6.5-meter-diameter mirror. The NASA just made a first test shot with the NIR Cam (Near Infrared Camera) of the JWST, and it’s already sublime despite the remaining imperfections (still a little grainy, monochrome): the picture in question reveals the star 2MASS J17554042+6551277 (bless you!), located in the constellation of the Dragon . The mirror is so sensitive that despite the focus on 2MASS-etc. we can see other stars and even galaxies in the background. Really fantastic!

James Webb first mirror photo

Note here that the reddish color is artificial (red filter), a false color that allows us to distinguish what would otherwise be invisible to our eyes (the NIRCam indeed captures in the infrared). Now that this alignment phase is complete, the engineers are starting the optimization and refinement phase, in particular to properly align the other instruments on board the JWST with the mirror (NIRSpec spectrograph, Miri infrared camera). The first real observations of James Webb will start during the month of July 2022.

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