                        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 October 5

                              M27: Not a Comet
       Image Credit & Copyright: Francesco Sferlazza, Franco Sgueglia

   Explanation: While hunting for comets in the skies above 18th century
   France, astronomer Charles Messier diligently kept a list of the things
   encountered during his telescopic expeditions that were definitely not
   comets. This is number 27 on his now famous not-a-comet list. In fact,
   21st century astronomers would identify it as a planetary nebula, but
   it's not a planet either, even though it may appear round and
   planet-like in a small telescope. Messier 27 (M27) is an excellent
   example of a gaseous emission nebula created as a sun-like star runs
   out of nuclear fuel in its core. The nebula forms as the star's outer
   layers are expelled into space, with a visible glow generated by atoms
   excited by the dying star's intense but invisible ultraviolet light.
   Known by the popular name of the Dumbbell Nebula, the beautifully
   symmetric interstellar gas cloud is over 2.5 light-years across and
   about 1,200 light-years away in the constellation Vulpecula. This
   impressive color image highlights details within the well-studied
   central region and fainter, seldom imaged features in the nebula's
   outer halo.

                     Tomorrow's picture: a comet's tale
     __________________________________________________________________

       Authors & editors: Robert Nemiroff (MTU) & Jerry Bonnell (UMCP)
            NASA Official: Phillip Newman Specific rights apply.
                NASA Web Privacy Policy and Important Notices
                      A service of: ASD at NASA / GSFC,
                           NASA Science Activation
                             & Michigan Tech. U.

