                        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 January 1
    A spiral galaxy with big blue spiral arms is shown with a center that
      appears more yellow. Please see the explanation for more detailed
                                information.

                   NGC 1232: A Grand Design Spiral Galaxy
                 Image Credit: FORS, 8.2-meter VLT Antu, ESO

   Explanation: Galaxies are fascinating not only for what is visible, but
   for what is invisible. Grand spiral galaxy NGC 1232, captured in detail
   by one of the Very Large Telescopes, is a good example. The visible is
   dominated by millions of bright stars and dark dust, caught up in a
   gravitational swirl of spiral arms revolving about the center. Open
   clusters containing bright blue stars can be seen sprinkled along these
   spiral arms, while dark lanes of dense interstellar dust can be seen
   sprinkled between them. Less visible, but detectable, are billions of
   dim normal stars and vast tracts of interstellar gas, together wielding
   such high mass that they dominate the dynamics of the inner galaxy.
   Leading theories indicate that even greater amounts of matter are
   invisible, in a form we don't yet know. This pervasive dark matter is
   postulated, in part, to explain the motions of the visible matter in
   the outer regions of galaxies.

      Free APOD Lecture: January 9, 2024 to the Amateur Astronomers of
                           Association of New York
                       Tomorrow's picture: open space
     __________________________________________________________________

       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.

