                        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.

                               2023 October 28

                           The Ghosts of Gamma Cas
        Image Credit & Copyright: Guillaume Gruntz, Jean-François Bax

   Explanation: Gamma Cassiopeiae shines high in northern autumn evening
   skies. It's the brightest spiky star in this telescopic field of view
   toward the constellation Cassiopeia. Gamma Cas shares the
   ethereal-looking scene with ghostly interstellar clouds of gas and
   dust, IC 59 (top left) and IC 63. About 600 light-years distant, the
   clouds aren't actually ghosts. They are slowly disappearing though,
   eroding under the influence of energetic radiation from hot and
   luminous gamma Cas. Gamma Cas is physically located only 3 to 4
   light-years from the nebulae. Slightly closer to gamma Cas, IC 63 is
   dominated by red H-alpha light emitted as hydrogen atoms ionized by the
   star's ultraviolet radiation recombine with electrons. Farther from the
   star, IC 59 shows proportionally less H-alpha emission but more of the
   characteristic blue tint of dust reflected star light. The cosmic stage
   spans over 1 degree or 10 light-years at the estimated distance of
   gamma Cas and friends.

               Tomorrow's picture: ghosts of the Cepheus Flare
     __________________________________________________________________

       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.

