                        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 January 30
     A ball of stars containing thousands of stars is shown with mostly
    light colored stars but with some stars having vibrant colors. Please
             see the explanation for more detailed information.

                 Globular Star Cluster NGC 6355 from Hubble
            Image Credit: ESA/Hubble & NASA, E. Noyola, R. Cohen

   Explanation: Globular clusters once ruled the Milky Way. Back in the
   old days, back when our Galaxy first formed, perhaps thousands of
   globular clusters roamed our Galaxy. Today, there are less than 200
   left. Over the eons, many globular clusters were destroyed by repeated
   fateful encounters with each other or the Galactic center. Surviving
   relics are older than any Earth fossil, older than any other structures
   in our Galaxy, and limit the universe itself in raw age. There are few,
   if any, young globular clusters left in our Milky Way Galaxy because
   conditions are not ripe for more to form. The featured image shows a
   Hubble Space Telescope view of 13-billion year old NGC 6355, a
   surviving globular cluster currently passing near the Milky Way's
   center. Globular cluster stars are concentrated toward the image center
   and highlighted by bright blue stars. Most other stars in the frame are
   dimmer, redder, and just coincidently lie near the direction to NGC
   6355.

                       Tomorrow's picture: tails tales
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       Authors & editors: Robert Nemiroff (MTU) & Jerry Bonnell (UMCP)
            NASA Official: Phillip Newman Specific rights apply.
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                             & Michigan Tech. U.

