Spectropolarimetry of the rings in NGC6543

Schwarz, H.; Bendersky, C.; Corradi, R.
Bibliographical reference

American Astronomical Society Meeting 207, #08.13; Bulletin of the American Astronomical Society, Vol. 37, p.1163

Advertised on:
12
2005
Number of authors
3
IAC number of authors
0
Citations
0
Refereed citations
0
Description
Planetary nebula NGC6543 has a complex structure with a central hot bubble showing both point- and plane symmetry, and a large outer halo that is likely interacting with the local ISM. Between these two structures the HST has revealed a series of a least nine regularly spaced concentric circular rings that are faint and have low contrast. The origin of these rings, which have also been found in other PNe, is not clear. We have taken long-slit spectropolarimetry of these rings using ISIS on the 4.2 meter William Hershel Telescope. Due to the faintness of the rings, only the [OIII] 500.7nm line had sufficient SN to be of use. We determined the polarization degree and angle in various positions in the core, rings, and outer halo of NGC6543. Only the rings showed significant polarization at 4-5% in a symmetric pattern centered on the central star of the PN, making dust scattering in the rings the likely polarigenic mechanism. Our observations did not have sufficient spectral resolution to distiguish between the two main classes of models that attempt to explain these rings.