Related papers: The Physical Characteristics of Binary Central Sta…
Close binary central stars of planetary nebulae are key in constraining the poorly-understood common-envelope phase of evolution, which in turn is critical in understanding the formation of a wide-range of astrophysical phenomena (including…
The increase in discovered close binary central stars of planetary nebulae is leading to a sufficiently large sample to begin to make broader conclusions about the effect of close binary stars on common envelope evolution and planetary…
Only a handful of binary central stars of planetary nebulae (PNe) are known today, due to the difficulty of detecting their companions. Preliminary results from radial velocity surveys, however, seem to indicate that binarity plays a…
It is widely believed that central star binarity plays an important role in the formation and evolution of aspherical planetary nebulae, however observational support for this hypothesis is lacking. Here, we present the most recent results…
During the past 20 years, the idea that non-spherical planetary nebulae (PN) may need a binary or planetary interaction to be shaped was discussed by various authors. It is now generally agreed that the varied morphologies of PN cannot be…
It is now clear that central star binarity plays a key role in the formation and evolution of planetary nebulae, with a significant fraction playing host to close-binary central stars which have survived one or more common envelope…
Close-binary central stars of planetary nebulae offer a unique tool with which to study the critical and yet poorly understood common-envelope phase of binary stellar evolution. Furthermore, as the nebula itself is thought to comprise the…
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…
A growing number of close binary stars are being discovered among central stars of planetary nebulae. Recent and ongoing surveys are finding new systems and contributing to our knowledge of the evolution of close binary systems. The push to…
It is now clear that a binary formation pathway is responsible for a significant fraction of planetary nebulae, and this increased sample of known binaries means that we are now in a position to begin to constrain their influence on the…
Close binary interactions perform a key role in the formation and shaping of planetary nebulae. However only a small fraction of Galactic planetary nebulae are known to host close binary systems. Many such systems are detectable through…
I list the 16 planetary nebulae (PNe) known to contain close-binary nuclei, and show that the nebulae generally have axisymmetric structures, including elliptical, bipolar, or ring morphologies. The orbital periods range from 2.7 hr to 16…
There is no quantitative theory to explain why a high 80% of all planetary nebulae are non-spherical. The Binary Hypothesis states that a companion to the progenitor of a central star of planetary nebula is required to shape the nebula and…
A current issue in the study of planetary nebulae with close binary central stars is the extent to which the binaries affect the shaping of the nebulae. Recent studies have begun to show a high coincidence rate between nebulae with…
This paper reviews our knowledge on binary central stars of planetary nebulae and presents some personal opinions regarding their evolution. Three types of interactions are distinguished: type I, where the binary companion induces the mass…
It is now clear that a binary pathway is responsible for a significant fraction of planetary nebulae, and the continually increasing sample of known central binaries means that we are now in a position to begin to use these systems to…
A thorough search of the OGLE-III microlensing project has more than doubled the total sample of PNe known to have close binary central stars. These discoveries have enabled close binary induced morphological trends to be revealed for the…
Why 80% of planetary nebulae are not spherical is not yet understood. The Binary Hypothesis states that a companion to the progenitor of the central star of a planetary nebula is required to shape the nebula and even for a planetary nebula…
Binarity has been hypothesised to play an important, if not ubiquitous, role in the formation of planetary nebulae (PNe). Yet there remains a severe paucity of known binary central stars required to test the binary hypothesis and to place…
Close binary central stars of planetary nebulae (PNe) must have formed through a common envelope evolution during the giant phase experienced by one of the stars. Transfer of the angular momentum from the binary system to the envelope leads…