Planetary nebulae in the SMC

Using the ESO 2.2m telescope with the 8K x 8K mosaic CCD, we surveyed 2.8 square degrees (similar to1.6degrees x 1.7degrees) of the SMC to search for faint planetary nebulae (PN). In this region, 34 PN were previously known; we identified 25 new objects. All of these are faint and have been spectroscopically confirmed. We estimate that there should be similar to140 PN in the entire SMC to the limits of a survey like this one, which is complete to 6 mug down the planetary nebula luminosity function (PNLF). For a complete survey (8 mug down the PNLF), there should be similar to220 PN. A strong new feature is evident in the PNLF as a deficiency at 4 mags below the brightest PN. The survey spectra that were used to confirm the candidates as PN show that the fainter PN exhibit a higher incidence (similar to28%) of strong [N II] emission (where I([N II]/I(Halpha) > 1) relative to the bright Sanduleak et al. (1978) sample (similar to6%). We propose that the very faint SMC PN are selectively biased toward the chemically enriched Type I objects derived from younger, more massive progenitors.