                        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 August 13
   A bright nebula occupies the center of the frame. The nebula is complex
    but roughly tan in the center and red around the edges. In the center
       are four bright blue stars. Please see the explanation for more
                            detailed information.

                      Trapezium: In the Heart of Orion
    Image Credit: Data: Hubble Legacy Archive, Processing: Robert Gendler

   Explanation: What lies in the heart of Orion? Trapezium: four bright
   stars, that can be found near the center of this sharp cosmic portrait.
   Gathered within a region about 1.5 light-years in radius, these stars
   dominate the core of the dense Orion Nebula Star Cluster. Ultraviolet
   ionizing radiation from the Trapezium stars, mostly from the brightest
   star Theta-1 Orionis C powers the complex star forming region's entire
   visible glow. About three million years old, the Orion Nebula Cluster
   was even more compact in its younger years and a dynamical study
   indicates that runaway stellar collisions at an earlier age may have
   formed a black hole with more than 100 times the mass of the Sun. The
   presence of a black hole within the cluster could explain the observed
   high velocities of the Trapezium stars. The Orion Nebula's distance of
   some 1,500 light-years make it one of the closest candidate black holes
   to Earth.

       Tomorrow's picture: when the Sky is serene and the Moon absent
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       Authors & editors: Robert Nemiroff (MTU) & Jerry Bonnell (UMCP)
            NASA Official: Amber Straughn Specific rights apply.
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                           NASA Science Activation
                             & Michigan Tech. U.

