Rapid evolution of [WC] stars in the Magellanic Clouds
  We obtained new spectra of fourteen Magellanic Cloud planetary nebulae with
the South African Large Telescope to determine heating rates of their central
stars and to verify evolutionary models of post-asymptotic giant branch stars.
We compared new spectra with observations made in previous years. Five
planetary nebulae showed an increase in excitation over time. Four of their
central stars exhibit [WC] features in their spectra, including three new
detections. This raises the total number of [WC] central stars of PNe in the
Magellanic Clouds to ten. We compared determined heating rates of the four [WC]
central stars with the He-burning post-asymptotic giant branch evolutionary
tracks and the remaining star with the H-burning tracks. Determined heating
rates are consistent with the evolutionary models for both H and He-burning
post-asymptotic giant branch stars. The central stars of the PNe that show the
fastest increase of excitation are also the most luminous in the sample. This
indicates that [WC] central stars in the Magellanic Clouds evolve faster than
H-burning central stars, and they originate from more massive progenitors.
