3 research outputs found
HST Measurements of the Expansion of NGC 6543: Parallax Distance and Nebular Evolution
The optical expansion parallax of NGC 6543 has been detected and measured
using two epochs of HST images separated by a time baseline of only three
years. We have utilized three separate methods of deriving the angular
expansion of bright fiducials, the results of which are in excellent agreement.
We combine our angular expansion estimates with spectroscopically obtained
expansion velocities to derive a distance to NGC 6543 of 1001269 pc. The
deduced kinematic age of the inner bright core of the nebula is 1039259
years; however, the kinematic age of the polar caps that surround the core is
larger - perhaps the result of deceleration or earlier mass ejection. The
morphology and expansion patterns of NGC 6543 provide insight into a complex
history of axisymmetric, interacting stellar mass ejections.Comment: Accepted for publication in AJ. 18 pages. 6 figure