HST Surveys of Magellanic Cloud Planetary Nebulae

Richard Shaw
NOAO, Tucson, AZ, USA


A number of surveys of Magellanic Cloud Planetary Nebulae (MCPNe) have been conducted over the last 13 years or so with the Hubble Space Telescope. These surveys have yielded images of over 100 LMC and over 30 SMC nebulae at the bright end of the PN luminosity function, with a resolution comparable to that of ground-based surveys of Galactic PNe. By virtue of their location in nearby galaxies, the distances to individual nebulae in these samples are known to an accuracy of better than 10%, which is remarkable by the standards of Galactic PNe. These samples, while in no sense complete,are reasonably large and are substantially unaffected by foreground reddening.

The HST-selected MCPN samples offer considerable insight into physical properties of PNe and their central stars (size, morphology, surface brightness; and CS luminosity, temerature and mass), as well as evolutionary properties that depend upon them (e.g., decline of surface brightness with age, size distribution, CS mass distribution). Combined with spectra in the literature, it is now possible to probe correlations of chemical and nebular physical properties with a precision unattainable with Galactic PNe, and from this gain deep insight into the formation and evolution of PNe, the connection of the PN evolution to that of their central stars, and the dependency of these phenomena on the metallicity and other properties of their host galaxies. This talk will summarize the broad properties of the HST samples of MCPNe, and the implications for our understanding of this phase of stellar evolution.