This image was the result of combining my Hubble image created from 2011 WFC3 data and data from the Subaru Telescope (8.2m) in Hawaii, processed by Robert Gendler.
He kindly shared the data and the final result is an astonishing image showing the outer shells of the M57 planetary nebula.
More info about this nebula can be found here.
Based on observations made with the NASA/ESA Hubble Space Telescope, and obtained from the Hubble Legacy Archive, which is a collaboration between the Space Telescope Science Institute (STScI/NASA), the Space Telescope European Coordinating Facility (ST-ECF/ESA) and the Canadian Astronomy Data Centre (CADC/NRC/CSA).
M57 Hubble/Subaru 8.2 m Hawaii combination – outer ring,