NOAO >   Observing Info >   Approved Programs >   2011B-0339

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Proposal Information for 2011B-0339


PI: Todd Hillwig, Valparaiso University, todd.hillwig@valpo.edu
Address: Physics Department, 1610 Campus Drive, Valparaiso, IN 46383, USA

CoI: David Frew, Macquarie University
CoI: Orsola De Marco, Macquarie University
CoI: Dimitri Douchin, Macquarie University

Title: Detecting Close Binary Central Stars of Planetary Nebulae: The Photometric Monitoring Campaign

Abstract: Our understanding of close binary stars with a compact companion has a broad impact on astrophysics. Since most such systems include a white dwarf, and all have gone through a common envelope phase, studying these systems in planetary nebulae provides a window to the beginning of this evolutionary stage. The sample of close binaries in planetary nebulae is approaching a statistically significant number. Past surveys have shown the fraction of planetary nebula central stars that are close binaries to be between 15 and 20 percent, but these surveys have suffered from strong selection effect biases. We now have a reliable volume-limited sample of planetary nebulae out to 2 kpc which can be surveyed to determine a reliable binary fraction for close binary central stars of planetary nebulae and provide more targets to add to the known binary sample. Knowledge of the binary fraction in planetary nebulae, classification of discovered binaries, and correlation of binarity with the surrounding ejected common envelope will greatly improve our understanding of the formation of astrophysically important objects like supernova Ia progenitors, cataclysmic variables, and subdwarf O and B stars. We propose a single-filter photometric monitoring campaign in both hemispheres of the 2 kpc volume-limited sample of planetary nebulae.


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NOAO >   Observing Info >   Approved Programs >   2011B-0339

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