                        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.

                                2025 April 4

                              Hickson 44 in Leo
                     Image Credit & Copyright: Jiang Wu

   Explanation: Scanning the skies for galaxies, Canadian astronomer Paul
   Hickson and colleagues identified some 100 compact groups of galaxies,
   now appropriately called Hickson Compact Groups. The four prominent
   galaxies seen in this intriguing telescopic skyscape are one such
   group, Hickson 44. The galaxy group is about 100 million light-years
   distant, far beyond the spiky foreground Milky Way stars, toward the
   constellation Leo. The two spiral galaxies in the center of the image
   are edge-on NGC 3190 with its distinctive, warped dust lanes, and
   S-shaped NGC 3187. Along with the bright elliptical, NGC 3193 (above
   and left) they are also known as Arp 316. The spiral toward the lower
   right corner is NGC 3185, the 4th member of the Hickson group. Like
   other galaxies in Hickson groups, these show signs of distortion and
   enhanced star formation, evidence of a gravitational tug of war that
   will eventually result in galaxy mergers on a cosmic timescale. The
   merger process is now understood to be a normal part of the evolution
   of galaxies, including our own Milky Way. For scale, NGC 3190 is about
   75,000 light-years across at the estimated distance of Hickson 44.

                      Tomorrow's picture: light-weekend
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       Authors & editors: Robert Nemiroff (MTU) & Jerry Bonnell (UMCP)
            NASA Official: Amber Straughn Specific rights apply.
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