LMC SMP 64 : the youngest planetary nebula ?

The planetary nebula SMP 64 in the Large Magellanic Cloud is shown to possess several properties which set it apart from the general PN population. These are an extremely high central electron density, a strong radial density gradient, and a central star with a very low effective temperature, T(eff) = 31,500 K. However, the luminosity of the central star is 6400 solar luminosities, implying a core mass of 0.62 solar mass, typical of the Magellanic Cloud population of planetary nebulae. It is concluded that the central star of SMP 64 has only just reached a temperature high enough to ionize a portion of the material ejected during the asymptotic giant branch evolution of the central star. 25 refs.