{'fraction_non_alphanumeric': 0.02313624678663239, 'fraction_numerical': 0.0, 'mean_word_length': 5.282258064516129, 'pattern_counts': {'":': 0, '<': 0, '<?xml version=': 0, '>': 0, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
Expansion Velocities of Planetary Nebulae with [WC] Central Stars

High resolution spectra have been used to determine the expansion velocities of a large sample of planetary nebulae around [WC] central stars. The results are compared with expansion velocities of non-WR planetary nebulae. All the data were obtained in a consistent way. We find that WRPNe have larger expansion velocities and larger turbulence than non-WRPNE, demonstrating that the mechanical energy of the massive [WC] stellar wind strongly affects the kinematical behavior of nebulae. A weak relation between stellar temperature and expansion velocities has been found for WRPNe, indicating that older nebulae expand faster. This could be useful in testing the evolutionary sequence proposed for [WC] stars.