                        Astronomy Picture of the Day

    Discover the cosmos! Each day a different image or photograph of our
      fascinating universe is featured, along with a brief explanation
                    written by a professional astronomer.

                                2022 July 13

                           Webb's First Deep Field
                 Image Credit: NASA, ESA, CSA, STScI, NIRCam

   Explanation: This is the deepest, sharpest infrared image of the cosmos
   so far. The view of the early Universe toward the southern
   constellation Volans was achieved in 12.5 hours of exposure with the
   NIRCam instrument on the James Webb Space Telescope. Of course the
   stars with six visible spikes are well within our own Milky Way. That
   diffraction pattern is characteristic of Webb's 18 hexagonal mirror
   segments operating together as a single 6.5 meter diameter primary
   mirror. The thousands of galaxies flooding the field of view are
   members of the distant galaxy cluster SMACS0723-73, some 4.6 billion
   light-years away. Luminous arcs that seem to infest the deep field are
   even more distant galaxies though. Their images are distorted and
   magnified by the dark matter dominated mass of the galaxy cluster, an
   effect known as gravitational lensing. Analyzing light from two
   separate arcs below the bright spiky star, Webb's NIRISS instrument
   indicates the arcs are both images of the same background galaxy. And
   that galaxy's light took about 9.5 billion years to reach the James
   Webb Space Telescope.

                     Tomorrow's picture: closer to home
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       Authors & editors: Robert Nemiroff (MTU) & Jerry Bonnell (UMCP)
            NASA Official: Phillip Newman Specific rights apply.
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                             & Michigan Tech. U.

