Ongoing surveys for close binary central stars and wider implications

Abstract

Binary central stars have long been invoked to explain the vexing shapes of planetary nebulae (PNe) despite there being scant direct evidence to support this hypothesis. Modern large-scale surveys and improved observing strategies have allowed us to significantly boost the number of known close binary central stars and estimate at least 20% of PNe have close binary nuclei that passed through a common-envelope (CE) phase. The larger sample of post-CE nebulae appears to have a high proportion of bipolar nebulae, low-ionisation structures (especially in SN1987A-like rings) and polar outflows or jets. These trends are guiding our target selection in ongoing multi-epoch spectroscopic and photometric surveys for new binaries. Multiple new discoveries are being uncovered that further strengthen the connection between post-CE trends and close binaries. These ongoing surveys also have wider implications for understanding CE evolution, low-ionisation structure and jet formation, spectral classification of central stars, asymptotic giant branch (AGB) nucleosynthesis and dust obscuration events in PNe.

To appear in IAU Symposium 283: Planetary Nebulae, an Eye to the Future. 4 pages, 1 figure

References in corpus (5)

• Young Planetary Nebulae: Hubble Space Telescope Imaging and a New Morphological Classification System
• Nucleosynthesis Predictions for Intermediate-Mass AGB Stars: Comparison to Observations of Type I Planetary Nebulae
• The Necklace: equatorial and polar outflows from the binary central star of the new planetary nebula IPHASXJ194359.5+170901
• ETHOS 1: A high latitude planetary nebula with jets forged by a post common envelope binary central star
• K 1-6: an asymmetric planetary nebula with a binary central star