                        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.

                              2024 November 12
      A starfield is shown with a unusual textured nebula in the center
   colored in brown with blue trimmings. Diffuse red nebula appear around
     the edges. In the center is an opaque brown object. Please see the
                 explanation for more detailed information.

                        NGC 6888: The Crescent Nebula
                     Image Credit & Copyright: Team ARO

   Explanation: How was the Crescent Nebula created? Looking like an
   emerging space cocoon, the Crescent Nebula, visible in the center of
   the featured image, was created by the brightest star in its center. A
   leading progenitor hypothesis has the Crescent Nebula beginning to form
   about 250,000 years ago. At that time, the massive central star had
   evolved to become a Wolf-Rayet star (WR 136), shedding its outer
   envelope in a strong stellar wind, ejecting the equivalent of our Sun's
   mass every 10,000 years. This wind impacted surrounding gas left over
   from a previous phase, compacting it into a series of complex shells,
   and lighting it up. The Crescent Nebula, also known as NGC 6888, lies
   about 4,700 light-years away in the constellation of Cygnus. Star WR
   136 will probably undergo a supernova explosion sometime in the next
   million years.

                Jigsaw Challenge: Astronomy Puzzle of the Day
                       Tomorrow's picture: open space
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       Authors & editors: Robert Nemiroff (MTU) & Jerry Bonnell (UMCP)
            NASA Official: Amber Straughn Specific rights apply.
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                           NASA Science Activation
                             & Michigan Tech. U.

