| Emission nebula | |
|---|---|
| Planetary nebula | |
 Composite image using optical images from the HST and X-ray data from the Chandra X-ray Observatory. | |
| Observation data: J2000 epoch | |
| Right ascension | 17h 58m 33.423s[1] |
| Declination | +66° 37′ 59.52″[1] |
| Distance | 3.3±0.9 kly (1.0±0.3 kpc)[2] ly |
| Apparent magnitude (V) | 9.8B[1] |
| Apparent dimensions (V) | Core: 20″[2] |
| Constellation | Draco |
| Physical characteristics | |
| Radius | Core: 0.2 ly[note 1] ly |
| Absolute magnitude (V) | −0.2+0.8 −0.6B[note 2] |
| Notable features | complex structure |
| Designations | NGC 6543,[1] Snail Nebula,[1] Sunflower Nebula,[1] (includes IC 4677),[1] Caldwell 6 |
The Cat's Eye Nebula (also known as NGC 6543 and Caldwell 6) is a planetary nebula in the northern constellation of Draco, discovered by William Herschel on February 15, 1786. It was the first planetary nebula whose spectrum was investigated by the English amateur astronomer William Huggins, demonstrating that planetary nebulae were gaseous and not stellar in nature. Structurally, the object has had high-resolution images by the Hubble Space Telescope revealing knots, jets, bubbles and complex arcs, being illuminated by the central hot planetary nebula nucleus (PNN).[3] It is a well-studied object that has been observed from radio to X-ray wavelengths. At the centre of the Cat's Eye Nebula is a dying Wolf Rayet star, the sort of which can be seen in the Webb Telescope's image of WR 124. The Cat's Eye Nebula's central star shines at magnitude +11.4. Hubble Space Telescope images show a sort of dart board pattern of concentric rings emanating outwards from the centre.
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