English: The ring of light surrounding the centre of the galaxy NGC 6505, captured by ESA’s Euclid telescope, is a stunning example of an Einstein ring. NGC 6505 is acting as a gravitational lens, bending light from a galaxy far behind it. The almost perfect alignment of NGC 6505 and the background galaxy has bent and magnified the light from the background galaxy into a spectacular ring. This rare phenomenon was first theorised to exist by Einstein in his general theory of relativity.

This wide field shows the extended stellar halo of NGC 6505 and showcases the Einstein ring, surrounded by colourful foreground stars and background galaxies.

Image description: A sea of colourful stars and galaxies appear to swim in the vast blackness of space around a hazy halo at centre stage. In the middle of the image, the fuzzy-looking bulb of light in a warm shade of yellow extends around a small bright spot, nestled within a thin light circle that appears to be drawn closely around it. As we follow the central halo’s rim outwards, its brightness dims and blends smoothly into its surroundings. Here, extended discs of shades ranging from a warm purple to golden yellow, and piercing dots of light with sharp diffraction spikes are spread evenly across the image.