Different Filters, Different Telescopes,
Same Beautiful Planetary Nebula

NGC 6543, Cat's Eye Nebula Imaged with Hubble
Credits: (left) NASA, ESA, J.P. Harrington and K.J. Borkowski (U. Maryland)
(right) NASA, STScI, and Z. Levay

These two images of the Cat's Eye Nebula were both taken with the Hubble Space Telescope. The image on the left was taken in 1994 with the Wide Field Planetary Camera 2 (WFPC2) in filters that isolate hydrogen, oxygen, and nitrogen. The image on the right uses a sulfur filter taken with WFPC2 and combines it with hydrogen and oxygen filters taken in 2002 with the Advanced Camera for Surveys High Resolution Camera (ACS/HRC). (Note: the red line in the image on the right is an artifact of the HRC "occulting finger" used to block out starlight on bright sources.)

NGC 6543, Cat's Eye Nebula Imaged with NOT
Credits: (left) R. Corradi (Isaac Newton Group) and D. Goncalves (Inst. Astrofisica de Canarias)
(right) Nordic Optical Telescope and R. Corradi (Isaac Newton Group of Telescopes, Spain)

The next two images are also of the Cat's Eye Nebula, taken with the ground-based Nordic Optical Telescope (NOT), located on the island of La Palma, in the Canary Islands. Notice that the wide field of view of the ground-based telescope shows nebulosity out beyond the central region that was imaged by Hubble. Both images were taken by astronomer, Romano Corradi, in two narrow-band filters: nitrogen and oxygen. The images differ in the assignment of the color scheme used to show the differing filters. The left image shows nitrogen in red and oxygen in green and blue shades. The right image shows oxygen in blue and nitrogen in red.

This image of the Cat's Eye Nebula shows the full extent of the ACS images that are not visible in the release image or the HRC images on this page. Three more pointings of the ACS Wide Field Camera would be necessary to cover the faint outer shell structure.

Credit: NASA, STScI, and Z. Levay

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