| Issue |
EAS Publications Series
Volume 71-72, 2015
The Physics of Evolved Stars: A Conference Dedicated to the Memory of Olivier Chesneau
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|---|---|---|
| Page(s) | 117 - 120 | |
| Section | Binaries | |
| DOI | https://doi.org/10.1051/eas/1571024 | |
| Published online | 01 December 2015 | |
E. Lagadec, F. Millour and T. Lanz (eds)
EAS Publications Series, 71–72 (2015) 117-120
The Role of Binarity in Wolf-Rayet Central Stars of Planetary Nebulae
1 South African Astronomical Observatory, PO Box 9, Observatory, 7935, South Africa
2 Southern African Large Telescope Foundation, PO Box 9, Observatory, 7935, South Africa
3 Instituut voor Sterrenkunde, KU Leuven, Celestijnenlaan 200D bus 2401, 3001 Leuven, Belgium
4 Astrophysics, Cosmology and Gravity Centre, Department of Astronomy, University of Cape Town, Private Bag X3, Rondebosch 7701, South Africa
5 South African Astronomical Observatory, PO Box 9, Observatory, 7935, South Africa
Over a hundred planetary nebulae (PNe) are known to have H-deficient central stars that mimic the spectroscopic appearance of massive Wolf-Rayet stars. The formation of these low-mass Wolf-Rayet stars, denoted [WR] stars, remains poorly understood. While several binary formation scenarios have been proposed, there are too few [WR] binaries known to determine their feasibility. Out of nearly 50 post-common-envelope (post-CE) binary central stars known, only PN G222.8−04.2 ([WC7], P = 1.26 d) and NGC 5189 ([WO1], P = 4.05 d) have a [WR] component. The available data suggests that post-CE central stars with [WR] components lack main sequence companions and have a wider orbital separation than typical post-CE binaries. There is also some indirect evidence for wide binaries that could potentially lead to the discovery of more [WR] binaries.
© EAS, EDP Sciences, 2015