                        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 January 29
   A bright spot at the center is surrounded by many concentric rings. The
    rings are nearly -- but not exactly -- circular in appearance. Please
             see the explanation for more detailed information.

                     Dust Shells around WR 140 from Webb
    Image Credit: NASA, ESA, CSA, STScI, E. Lieb (U. Denver), R. Lau (NSF
                      NOIRLab), J. Hoffman (U. Denver)

   Explanation: What are those strange rings? Rich in dust, the rings are
   likely 3D shells -- but how they were created remains a topic of
   research. Where they were created is well known: in a binary star
   system that lies about 6,000 light years away toward the constellation
   of the Swan (Cygnus) -- a system dominated by the Wolf-Rayet star WR
   140. Wolf-Rayet stars are massive, bright, and known for their
   tumultuous winds. They are also known for creating and dispersing heavy
   elements such as carbon, which is a building block of interstellar
   dust. The other star in the binary is also bright and massive -- but
   not as active. The two great stars joust in an oblong orbit as they
   approach each other about every eight years. When at closest approach,
   the X-ray emission from the system increases, as, apparently, does the
   dust expelled into space -- creating another shell. The featured
   infrared image by the Webb Space Telescope resolves greater details and
   more dust shells than ever before. Images taken over consecutive years
   show the shells moving outward.

                       Tomorrow's picture: open space
     __________________________________________________________________

       Authors & editors: Robert Nemiroff (MTU) & Jerry Bonnell (UMCP)
            NASA Official: Amber Straughn Specific rights apply.
                  NASA Web Privacy, Accessibility, Notices;
                      A service of: ASD at NASA / GSFC,
                           NASA Science Activation
                             & Michigan Tech. U.

