A survey for hot central stars of planetary nebulae – I. Methods and first results

Abstract

We present the results of initial spectrographic followup with the Very Large Telescope (UT3, Melipal) for K s ≥ 14 Galactic plane C iv emission-line candidates in the near-infrared (NIR). These 7 faint stars all display prominent He i and C iv emission lines characteristic of a carbonrich Wolf-Rayet star. They have NIR colours which are much too blue to be those of distant, classical WR stars. The magnitudes and colours are compatible with those expected for central stars of planetary nebulae, and are likely to come from massive progenitor populations, and themselves be more massive than any sample of planetary nebulae known. Our survey has identified thousands of such candidates.