The Cat’s Eye star is the hot central star of the Cat’s Eye Nebula, a dying star whose fierce wind shapes one of the most intricate nebulae known.
At a glance
| type | blue star (class O) |
|---|---|
| distance from the Sun | 4,450 light-years (1.36 kpc) |
| its light left it | 4,450 years ago |
| luminosity | 5,000 × the Sun |
| radius | 0.37 × the Sun |
| surface temperature | 80,000 K |
Read off the piece’s own catalogue, the same values it draws with.
About Cat's Eye star
The Cat’s Eye Nebula, NGC 6543, in Draco is a planetary nebula with an unusually complex structure: overlapping shells, jets and knots, surrounded by faint concentric rings that record episodes of mass loss before the main nebula formed.
At the centre is a very hot star, the nearly bare core of the original star, not yet a white dwarf. Its spectrum shows a fast, dense wind, and X-ray observations reveal gas heated far beyond the star’s own surface temperature where that wind has slammed into the slower material shed earlier.
The Cat’s Eye was the first planetary nebula whose light was split into a spectrum, which showed bright emission lines: the nebula was glowing gas, not a mass of unresolved stars.
What you see in the piece
Fly to the Cat’s Eye Nebula and its central star is a small blue-white point; it is hot enough to be blue and to light the gas around it.
Measured or modelled
The tangled structure of the nebula is often attributed to a hidden companion star, but that companion has not been found; it is a hypothesis.
Questions
What is at the centre of the Cat’s Eye Nebula?
A very hot star, the nearly exposed core of a dying star, with a surface around 80,000 K and a fast wind that shapes the nebula.
Why is the Cat’s Eye Nebula important?
It was the first planetary nebula studied with a spectroscope, which proved that such nebulae are clouds of glowing gas.