Related papers: Observed Planetary Nebulae as Descendants of Inter…
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…
Roughly half of Solar-type planet hosts have stellar companions, so understanding how these binary companions affect the formation and evolution of planets is an important component to understanding planetary systems overall. Measuring the…
We have attempted to establish an observational evidence for presence of distant companions which may have acquired and/or absorbed the angular momentum during evolution of multiple systems thus facilitating or enabling formation of contact…
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…
We review the evolution of our understanding of the planetary nebulae phenomenon and their place in the scheme of stellar evolution. The historical steps leading to our current understanding of central star evolution and nebular formation…
We examine the images of hundreds of planetary nebulae (PNe) and find that for about one in six PNe the morphology is too `messy' to be accounted for by models of stellar binary interaction. We speculate that interacting triple stellar…
Binaries containing compact objects, if viewed close to edge on, can produce periodic brightening events under certain conditions on the masses, radii, and binary separation. Such flares are caused by one object gravitational lensing the…
During the last years, many observational studies have revealed that binaries play an active role in the shaping of non spherical planetary nebulae. We review the different works that lead to the direct or indirect evidence for the presence…
The common envelope interaction is responsible for evolved close binaries. Among them are a minority of central stars of planetary nebula (PN). Recent observational results, however, point to most PN actually being in binary systems. We…
Planetary nebulae are thought to be formed when a slow wind from the progenitor giant star is overtaken by a subsequent fast wind generated as the star enters its white dwarf stage$^{1}$. A shock forms near the boundary between the winds,…
In a recent work Ciardullo et al. (1999) list 19 planetary nebulae surveyed by the Hubble Space Telescope for the presence of resolved visual binary companions of their central stars. For ten planetary nebulae they argue for probable…
Nearly every star known to host planets will become a white dwarf, and nearly 100 planet-hosts are now known to be accompanied by binary stellar companions. Here, we determine how a binary companion triggers instability in otherwise…
Significant numbers of free-floating planetary-mass objects have been discovered in nearby star-forming regions by the James Webb Space Telescope, including a substantial number (42) of Jupiter Mass Binary Objects ('JuMBOs') in the Orion…
Hot subdwarfs are core-helium burning stars that show lower masses and higher temperatures than canonical horizontal branch stars. They are believed to be formed when a red giant suffers an extreme mass-loss episode. Binary interaction is…
Planetary nebulae (PNe) are circumstellar gas ejected during an intense mass-losing phase in the the lives of asymptotic giant branch stars. PNe have a stunning variety of shapes, most of which are not spherically symmetric. The debate over…
The overall frequency and other statistical properties of binary systems suggest that star formation is intrinsically a complex and chaotic process, and that most binaries and single stars actually originate from the decay of multiple…
Common envelope events have been associated with the formation of a planetary nebulae since its proposition more than forty five years ago. However, until recently there have been doubts as to whether a common envelope while the donor is…
We show that there are strong links between certain types of asymmetrical Planetary Nebulae (PNe) and symbiotic stars. Symbiotics are binaries and several have extended optical nebulae all of which are asymmetrical and ~-40% are bipolar.…
The planet formation process and subsequent planet migration may lead to configurations resulting in strong dynamical interactions among the various planets. Well-studied possible outcomes include collisions between planets, scattering…
Stellar models of massive single stars are still plagued by major uncertainties. Testing and calibrating against observations is essential for their reliability. For this purpose one preferably uses observed stars that have never…