                        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.

                              2021 December 24

                             M1: The Crab Nebula
                  Image Credit & Copyright: Michael Sherick

   Explanation: The Crab Nebula is cataloged as M1, the first object on
   Charles Messier's famous 18th century list of things which are not
   comets. In fact, the Crab is now known to be a supernova remnant,
   debris from the death explosion of a massive star, witnessed by
   astronomers in the year 1054. This sharp, ground-based telescopic view
   combines broadband color data with narrowband data that tracks emission
   from ionized sulfur, hydrogen, and oxygen atoms to explore the tangled
   filaments within the still expanding cloud. One of the most exotic
   objects known to modern astronomers, the Crab Pulsar, a neutron star
   spinning 30 times a second, is visible as a bright spot near the
   nebula's center. Like a cosmic dynamo, this collapsed remnant of the
   stellar core powers the Crab's emission across the electromagnetic
   spectrum. Spanning about 12 light-years, the Crab Nebula is a mere
   6,500 light-years away in the constellation Taurus.

                    Tomorrow's picture: A Christmas Comet
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       Authors & editors: Robert Nemiroff (MTU) & Jerry Bonnell (UMCP)
            NASA Official: Phillip Newman Specific rights apply.
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