                        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 February 26
    A cluster of galaxies is shown with many galaxies around the cluster
    center. A close look at this center shows that it is encompassed by a
     narrow ring of light. Please see the explanation for more detailed
                                information.

                Einstein Ring Surrounds Nearby Galaxy Center
     Image Credit & Copyright: ESA, NASA, Euclid Consortium; Processing:
                     J.-C. Cuillandre, G. Anselmi, T. Li

   Explanation: Do you see the ring? If you look very closely at the
   center of the featured galaxy NGC 6505, a ring becomes evident. It is
   the gravity of NGC 6505, the nearby (z = 0.042) elliptical galaxy that
   you can easily see, that is magnifying and distorting the image of a
   distant galaxy into a complete circle. To create a complete Einstein
   ring there must be perfect alignment of the nearby galaxy's center and
   part of the background galaxy. Analysis of this ring and the multiple
   images of the background galaxy help to determine the mass and fraction
   of dark matter in NGC 6505's center, as well as uncover previously
   unseen details in the distorted galaxy. The featured image was captured
   by ESA's Earth-orbiting Euclid telescope in 2023 and released earlier
   this month.

                       Tomorrow's picture: open space
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       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.

