It is now clear that a binary evolutionary pathway is responsible for a significant fraction of all planetary nebulae, with some authors even going so far as to claim that binarity may be a near requirement for the formation of an observable nebula. This has led to the requirement that textbooks most likely need to be rewritten. Building upon the review of Jones and Boffin in Nature Astronomy (2017), this Springer Brief takes a first step in this direction. It offers the first expanded presentation of all the theoretical and observational support for the importance of binarity in the formation of planetary nebulae, initially focusing on common envelope evolution but also covering wider binaries. This book emphasises the wider impact of the field, highlighting the critical role binary central stars of planetary nebulae have in understanding a plethora of astrophysical phenomena, including type Ia supernovae, chemically peculiar stars and circumbinary exoplanets.

Autorentext

Henri Boffin received his PhD in 1993 for his work on the formation of barium stars and has since studied a variety of problems in relation to binary stars, as well as exoplanets. Most recently, he has shown the importance of binary stars in explaining planetary nebulae, including discovering the binary central star of Fleming 1, and pioneered the use of optical interferometry to study mass transfer in symbiotic stars. He is co-author of more than 100 referred papers and co-editor of 5 books. He was credited the discovery of 11 asteroids. Since 2003 he works at the European Southern Observatory (ESO).

David Jones received his PhD in 2011, from the University of Manchester's Jodrell Bank Centre for Astrophysics, for his work on the morphologies and kinematics of planetary nebulae. He has also worked at the European Southern Observatory's Paranal Observatory, the Universidad de Atacama and the Isaac Newton Group of Telescopes, and is currently based at the  Instituto de Astrofísica de Canarias (IAC) on the Spanish island of La Palma. He is the author of more than 50 refereed papers covering topics ranging from near-Earth asteroids to type Ia supernovae. Since 2018, he is a member of the organizing committee of the International Astronomical Union's Planetary Nebulae commission.

Inhalt
1. Introduction (10-15 pp)- stellar evolution of solar-like stars- explain what a planetary nebula (PN) is and their importance (bright objects that can be used as distant beacons to probe kinematics and chemistry of intergalactic and extragalactic medium)- presentation of observations of nebular lines- the prevailing model (GISW) and present the diversity in shapes (morphology and possible role of rotation and magnetic fields)- historical presentation of why binary CSPNe were proposed as proof that the common envelope process exists.
2. The common envelope process (10-15 pp)- mass transfer in binary systems- its importance for other objects (CVs, Type Ia SNe)- the CE modelling with the alpha and lambda prescription- numerical simulations of CE- open questions.
3. Close binaries in PNe (20-30 pp)- history of discoveries and the recent explosion in findings; ongoing surveys; what are the discovery methods?- photometric variations in close binaries and their limitations (elongation, irradiation)- modelling of known systems with main sequence systems- what is the current state of knowledge?- how does the period distribution compare to other samples, to theoretical models?- what is the close binary fraction? Is it what is expected?- importance of planets and the possibility of forming a second-generation of exoplanets- morphologies and their link to binarity/mass transfer (co-alignment, jets, etc.)- overabundance of double degenerate and connection with Type Ia and gravitational waves.
4. Chemical evidence for mass transfer (10-15 pp)- overabundance of Carbon in the Necklace as a sign of mass transfer; link with most recent numerical simulations of CE- The Abundance discrepancy problem- how are chemical abundances determined in PNe: ORL vs CEL; physics of nebula- correlation with orbital period.
5. Long period systems (10 pp)- discoveries- chemical abundances- link with Barium stars, post-RGB stars, post-AGB stars, symbiotic stars.
6. Binary fraction (10 pp)- close binaries - observed fraction and biases; Kepler observations- long period (Radial Velocity surveys)- infrared excess- what is the final fraction? Is it compatible with models? Problem of envelope mass? Why no A-F primaries?
7. Absence of binaries in proto-PNe (5 pp)
8. The PN Luminosity Function (5 pp)
9. Conclusion and outlook (5 pp)
References and index (5 pp)