                        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 27
    A complex orange and purple nebula with a complex texture is shown in
   front of a dark starfield. Please see the explanation for more detailed
                                information.

                        IC 418: The Spirograph Nebula
     Image Credit: NASA, ESA, and the Hubble Heritage Team (STScI/AURA);
                   Acknowledgement: R. Sahai (JPL) et al.

   Explanation: What is creating the strange texture of IC 418? Dubbed the
   Spirograph Nebula for its resemblance to drawings from a cyclical
   drawing tool, planetary nebula IC 418 shows patterns that are not well
   understood. Perhaps they are related to chaotic winds from the variable
   central star, which changes brightness unpredictably in just a few
   hours. By contrast, evidence indicates that only a few million years
   ago, IC 418 was probably a well-understood star similar to our Sun.
   Only a few thousand years ago, IC 418 was probably a common red giant
   star. Since running out of nuclear fuel, though, the outer envelope has
   begun expanding outward leaving a hot remnant core destined to become a
   white-dwarf star, visible in the image center. The light from the
   central core excites surrounding atoms in the nebula causing them to
   glow. IC 418 lies about 2000 light-years away and spans 0.3 light-years
   across. This false-color image taken from the Hubble Space Telescope
   reveals the unusual details.

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