Hubble Space Telescope observations of planetary nebulae in the Magellanic Clouds. I: The extreme type I SMP 83/WS 35

We have obtained Hubble Space Telescope Planetary Camera images in both the Hα and the [O III] λ5007 emission lines of the planetary nebula SMP 83 alias WS35, alias N66 in the Large Magellanic Cloud. By combining these results with optical and UV spectrophotometry, absolute flux measurements, and dynamical and density information, we have been able to construct a fully self-consistent nebular model. This proves that SMP 83 is an extremely massive type I object having a central star having an effective temperature of 170,000 K and a luminosity of nearly 3×10 4 L ○. . The core mass is estimated in the range 1.0-1.2 M ○. , for which the main-sequence mass was greater than ∼6 M ○. . The nebular abundances are higher than the average for the LMC and show evidence for hot-bottom burning