The planetary nebulae NGC 1535 and NGC 2022.

The forbidden O III and H-alpha expansion velocity fields within the planetary nebulae NGC 1535 and NGC 2022 have been obtained from Echelle spectrograms. NGC 1535 consists of two coaxial prolate spheroids of moderate ellipticity; NGC 2022 is a prolate spheroid surrounded by an almost spherical, fainter emitting region. The observed parameters for the two nebulae (nebular radius, expansion velocity, ionized mass, temperature and luminosity of the exciting star) can be explained in terms of the evolutionary model suggested by Sabbadin et al. (1984). Both objects are planetary nebulae in a rather early evolutionary phase, when planetaries are again optically thick, with NGC 2022 somewhat more evolved than NGC 1535 (i.e. closer to the transition from thick to thin).