• DOI:10.1093/mnras/stv074
• Corpus ID: 118600965

A radial velocity survey for post-common-envelope Wolf–Rayet central stars of planetary nebulae: first results and discovery of the close binary nucleus of NGC 5189

@article{Manick2015ARV,
  title={A radial velocity survey for post-common-envelope Wolf–Rayet central stars of planetary nebulae: first results and discovery of the close binary nucleus of NGC 5189},
  author={Rajeev Manick and Brent Miszalski and Vanessa A McBride},
  journal={Monthly Notices of the Royal Astronomical Society},
  year={2015},
  volume={448},
  pages={1789-1806}
}

• R. Manick, B. Miszalski, V. McBride
• Published 14 January 2015
• Physics, Geology
• Monthly Notices of the Royal Astronomical Society

The formation of Wolf-Rayet central stars of planetary nebulae ([WR] CSPNe) whose spectroscopic appearance mimics massive WR stars remains poorly understood. Least understood is the nature and frequency of binary companions to [WR] CSPNe that may explain their H-deficiency. We have conducted a systematic radial velocity (RV) study of 6 [WR] CSPNe to search for post-common-envelope (post-CE) [WR] binaries. We used a cross-correlation method to construct the RV time-series as successfully done for massive close binary WR stars. No significant RV variability was detected for the late-[WC] type nuclei of Hen 2-113, Hen 3-1333, PMR 2 and Hen 2-99. Significant, large-amplitude variability was found in the [WC4] nucleus of NGC 5315. In the [WO1] nucleus of NGC 5189 we discovered significant periodic variability that reveals a close binary with Porb = 4.04± 0.1 d. We measured a semi-amplitude of 62.3± 1.3 km s −1 that gives a companion mass of m2 > 0.5 M⊙ or m2 = 0.84 M⊙ (assuming i = 45 ◦ ). The most plausible companion type is a massive WD as found in Fleming 1. The spectacular nebular morphology of NGC 5189 fits the pattern of recently discovered post-CE PNe extremely well with its dominant low-ionisation structures (e.g. as in NGC 6326) and collimated outflows (e.g. as in Fleming 1). The anomalously long 4.04 d orbital period is either a once-off (e.g. NGC 2346) or it may indicate there is a sizeable population of [WR] binaries with massive WD companions in relatively wide orbits, perhaps influenced by interactions with the strong [WR] wind.