Cat’s Eye Nebula in Draco

NGC 6543 is 4. 4 minutes of arc from the current position of the north ecliptic pole, Less than ​1⁄10 of the 45 arc minutes between Polaris and the current location of the Earth’s northern axis of rotation. It is a convenient and accurate marker for the axis of rotation of the Earth’s ecliptic, around which the celestial North Pole rotates. It is also a good marker for the nearby “invariable” axis of the solar system, which is the center of the circles which every planet’s north pole, and the north pole of every planet’s orbit, make in the sky. Since motion in the sky of the ecliptic pole is very slow compared to the motion of the Earth’s north pole, its position as an ecliptic pole station marker is essentially permanent on the time-scale of human history, as opposed to the Pole Star, which changes every few thousand years.