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T.-H. Lee, L. Stanghellini (National Optical Astronomy Observatory), L. Ferrario, D. Wickramasinghe (The Australian National University)
We present high resolution echelle spectroscopy of central stars (CSs) of Southern bipolar planetary nebulae (PNe). The spectra were acquired with the ESO Multi-Mode Instrument (EMMI) on the 3.58 m New Technology Telescope (NTT) in February 2003. The objective of the observations is to determine the shaping mechanism of the highly bipolar structures, in particular, to look for Zeeman splits of the stellar lines casued by possible magnetic fields associated with the CSs. The presence of a magnetic field is a plausible explanation for the bipolar shaping of PNe, but to this day a clear detection of a Zeeman split in CS spectra has been elusive. Our aim is to detect fields (or their upper limits) down to 1000 Gauss, and correlate the results with nebular and stellar characteristics. Preliminary results show no signature of magnetic fields in most of our targets, and a possible detection in one of the cases analyzed so far. The data set offers further insight in the shaping mechanism, in particular, that of the rare optical P-Cygni profile probing strong CS winds.
The author(s) of this abstract have provided an email address for comments about the abstract: thlee@noao.edu
Bulletin of the American Astronomical Society, 37 #4
© 2005. The American Astronomical Soceity.