PI: Brent Miszalski, University of Hertfordshire, email@example.com
Address: Department of Physical Sciences, College Lane, Hatfield, HRT AL10 9AB, United Kingdom
CoI: Anthony Moffat, University of Montreal
CoI: Orsola De Marco, Macquarie University
CoI: Todd Hillwig, Valparaiso University
Title: A synoptic spectroscopic survey for binary central stars of planetary nebulae
Abstract: Common-envelope (CE) evolution is very poorly understood theoretically but is crucial to understanding the orbital period distribution, space density, birthrate and different types of post-CE binaries including Supernova Ia progenitors and low-mass X-ray binaries. Theoretical binary population synthesis models currently must rely upon post-CE populations whose orbital periods were altered by magnetic breaking and gravitational radiation. Observations of post-CE binaries can measure the fundamental parameter in these models, the envelope ejection efficiency, but such measurements are flawed if the orbital periods are unaltered from the end of the CE phase. To progress in the field a new population must be used whose orbital periods have not suffered angular momentum loss after the CE phase terminated. The post-CE central stars of planetary nebulae (CSPN), of which only 40 are known, fit this niche perfectly since their recently ejected nebula guarantees the "freshness" of the binary. Here we aim to dramatically increase the post-CE CSPN population, building a solid foundation for their exploitation as powerful probes of CE evolution. These discoveries will also provide much needed direct evidence for the shaping of PN by close binaries.
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