Cat's Eye Nebula
What is Cat's Eye Nebula?
Nebulae· Distance 3,300 ly. The most intricately structured planetary nebula known: eleven concentric shells puffed out by a dying star every 1,500 years, nested like an onion, famous as Hubble's green cat's eye. Close to the north celestial pole in Draco, it never sets from Korea.
📍 Visible from where you are right now — computed in your browser
bearing · altitude · rise time · best time tonight
Where Cat's Eye Nebula is in your sky right now: https://nowsky.org/solar/sky?sel=cat%27s eye nebula — location and time set automatically, no login.
Its place in the sky
A nebula, in the direction of Draco, spanning about 0.333 arcminutes of sky — 0 times the width of the full Moon.
Distance and scale
| Distance | ~3,300 ly |
|---|---|
| Size | ~0.4 ly core |
| Type | planetary nebula |
| Constellation | Draco |
Figures are representative approximations. Source: compiled from NASA and IAU public data.
Frequently asked
- How far is Cat's Eye Nebula from Earth?
- ~3,300 ly.
- What kind of object is Cat's Eye Nebula?
- planetary nebula.
- Where in the sky is Cat's Eye Nebula?
- In the direction of Draco.
- Where is Cat's Eye Nebula in the sky right now?
- Open the sky view for your location and time and it shows the position in the sky right now.
Why so intricate — a shape made by a companion
Inside the Cat's Eye lie several elliptical shells with different axes and jets that change direction, all tangled together. A single star shedding its envelope does not produce such a shape. The leading explanation is a companion orbiting the central star — its gravity gathers the outflowing material into a disk, the disk's axis precesses, and jets pointing in different directions at different times carve shells along several axes.
The companion has not been observed directly, and radial-velocity variations of the central star itself are unconfirmed, so the Cat's Eye remains the chief test case for the hypothesis that companions shape planetary nebulae. The eleven concentric shells outside are a separate matter — the trace of the star ejecting material regularly every 1,500 years — and the cause of that regularity is likewise debated, between a companion and pulsations of the star itself.
The nebula in depth
The Cat's Eye Nebula (NGC 6543) is a planetary nebula about 3,300 light-years away in Draco. William Herschel found it in 1786, and in 1864 William Huggins turned a spectroscope on it and proved for the first time that such nebulae are hot gas rather than unresolved stars. The core is only about 0.4 light-years wide, but the outer halo extends beyond five.
Hubble's 1994 image made it famous. Inside are interlocking elliptical shells and jets, and around them at least eleven concentric rings puffed out roughly every 1,500 years. Why the star pulsed so regularly is still unclear; a hidden companion star is the leading suspect. The central star's surface reaches about 80,000 K.
In the Sky view, look between the head of Draco and Ursa Minor, not far from Polaris. At declination +66° it stays above the horizon from Korea all year, climbing highest on summer evenings. As an 8th-magnitude disk it is hard to tell from a star in binoculars, but a telescope at high power shows a blue-green disk.
Related
Figures are representative approximations. Simulated positions use J2000 mean elements.