An empirical analysis of the stellar wind and Planetary Nebulae of the [WC10] central stars CPD–56° 8032 and He 2–113

Orsola de Marco, M. J. Barlow, P. J. Storey
1997 Symposium - International astronomical union  
[WC] stars are H–deficient central stars of PN which have developed a dense, fast stellar wind. Their spectra can mimic the spectra of massive (Min∼5OM⊙) Wolf-Rayet stars of the carbon sequence. Deriving their parameters is of importance both in understanding the PN and the Wolf-Rayet phenomena. Spectra of both objects were obtained at the AAT in May 1993 with the UCL Echelle Spectrograph (3500–9200 å, R=50,0000). The reddening, determined from comparing the Hβnebular line fluxes with radio
more » ... es from Purton et al. (MNRAS 128, 321, 1982), yielded E(B-V)=0.68 (CPD–56° 8032) and 1.00 (He 2–113). Distances are derived using two different methods and they agree within the relative uncertainties. They are 1.35 and 1.50 kpc for CPD–56° 8032 and He 2–113, respectively. The electron temperatures of the C ii line formation region in the wind is derived from a recombination line analysis (20,000 and 17,000 K for CPD–56° 8032 and He 2–113, respectively). From the same stellar wind recombination line analysis, we find C/He=0.12 and 0.16, together with O/He=0.19 and 0.25, for CPD–56° 8032 and He 2–113 respectively.
doi:10.1017/s0074180900129900 fatcat:ko4kj7rc2vblhao3mz4lrkrbje