2010A&A...509A..13P

We discuss the status of the A-type component of the binary central star in the peculiar planetary nebula HD 149427. We acquired low and high spectral resolution optical spectroscopy for the range 4500-9000Å. The analysis of the high resolution spectrum shows that the A-type star has an effective temperature of T_eff=8700±150K and a surface gravity of logg=2.3±0.4, corresponding to a spectral type A3-A4II. These parameters infer a luminosity estimate of log(L/L_☉)=3.69±0.32, implying a distance of 10±0.6kpc. The A-type star is slightly metal-poor; barium and strontium, two key elements for monitoring the s-process nucleosynthesis, are not enriched; nitrogen is enriched relative to Sun; while carbon and oxygen are underabundant. The photospheric abundance of the A-type giant star in HD 149427 is compared with the abundance in other types of stars at different evolutionary stages.