Based on 24h high speed photometry of the hybrid PG 1159 star Abell 43, we have detected 6 sighificant pulsations with periods between 2380 s and 6075 s. A short (4h) run on the almost spectroscopic twin NGC 7094 central star resulted in detection of 3 low amplitude pulsations with periods between 2000 s and 5000 s. The results are close to predictions for g-mode pulsations driven by the kappa-mechanism induced by the partial ionization of carbon and oxygen.
@article{arxiv.0705.2115,
title = {Abell 43: Longest period Planetary Nebula Nucleus variable},
author = {J. -E. Solheim and G. Vauclair and A. S. Mukadam and R. Janulis and V. Dobrovolskas},
journal= {arXiv preprint arXiv:0705.2115},
year = {2009}
}