                        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.

                              2026 February 16
      A star field shows colorful pill-shaped nebula extending from the
    bottom left toward the upper right. Colors include, from the outside
   in, red, green, and blue. Please see the explanation for more detailed
                                information.

                Unexplained Shocks Around a White Dwarf Star
            Image Credit: ESO, K. Iłkiewicz & S. Scaringi et al.;
             Text: Cecilia Chirenti (NASA GSFC, UMCP, CRESST II)

   Explanation: How is RXJ0528+2838 creating such shock waves? A recently
   discovered white dwarf star, the farther left of the two largest white
   spots, RXJ0528+2838, was found 730 light-years away from Earth. Most
   stars, when done fusing nuclei in their cores for energy, become red
   giant stars, the cores of which live on as faint dense white dwarfs
   that slowly cool down for the rest of time. White dwarfs are so dense
   that the only thing that stops them from collapsing further is quantum
   mechanics. In about 5 billion years, our Sun will become a white dwarf,
   too. The featured image, obtained with the European Southern
   Observatory’s Very Large Telescope, shows unexplained bow shocks around
   RXJ0528+2838, similar to the bow wave of water around a fast-moving
   ship. Astronomers don’t yet know what is powering these shocks, which
   have existed for at least 1,000 years. The red, green and blue colors
   represent trace amounts of glowing hydrogen, nitrogen and oxygen gas.

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       Authors & editors: Robert Nemiroff (MTU) & Jerry Bonnell (UMCP)
            NASA Official: Amber Straughn Specific rights apply.
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                             & Michigan Tech. U.

