Related papers: Shaping Planetary Nebulae and Related Objects
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…
I review some aspects related to the influence of planets on the evolution of stars before and beyond the main sequence. Some processes include the tidal destruction of a planet on to a very young main sequence star, on to a low mass main…
I discuss some observational properties of aspherical nebulae around massive stars, and conclusions inferred for how they may have formed. Whether or not these ideas are applicable to the shaping of planetary nebulae is uncertain, but the…
We present 2D hydrodynamical simulations of the transition of a proto-planetary nebula to a planetary nebula for central stars in binary systems that have undergone a common envelope event. After 1,000 yr of magnetically driven dynamics…
It is already known that about 10% of central stars of PNe are very short-period binaries (hours to days), which are detected through photometric variations. These must have been formed through common-envelope interactions in initially wide…
Planetary nebulae are formed by the matter ejected by low-to-intermediate mass stars (~0.8-8 times the mass of the Sun) towards the end of their lives. As hydrogen and then helium fuel sources run out, stars expand. During these giant…
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,…
Planetary Nebulae represent a powerful window into the evolution of low-intermediate mass stars that have undergone extensive mass-loss. The nebula manifests itself in an extremely wide variety of shapes, but exactly how the mass lost is…
We discuss the interaction of the slow wind blown by an asymptotic giant branch (AGB) star with a collimated fast wind (CFW) blown by its main sequence or white dwarf companion, at orbital separations in the range of several AU to about 200…
The role of central star binarity in the shaping of planetary nebulae (PNe) has been the subject of much debate, with single stars believed to be incapable of producing the most highly collimated morphologies. However, observational support…
The final expulsion of gas by a star as it forms a planetary nebula --- the ionized shell of gas often observed surrounding a young white dwarf --- is one of the most poorly understood stages of stellar evolution. Such nebulae form…
It is not yet clear whether magnetic fields play an essential role in shaping planetary nebulae (PNe), or whether stellar rotation alone and/or a close binary companion can account for the variety of the observed nebular morphologies. In a…
A review of recent observations of the kinematics of six objects that represent the broad range of phenomena called planetary nebulae (PNe) is presented. It is demonstrated that Hubble-type outflows are predominant, consequently it is…
This paper reports the results of the numerical study of the formation of aspherical Planetary Nebulae through the Generalised Interacting Winds Model, taking into account the effects caused by the evolving central star and fast wind. The…
Planetary nebulae (PNe) can be roughly categorized into several broad morphological classes. The high quality images of PNe acquired in recent years, however, have revealed a wealth of fine structures that preclude simplistic models for…
The status of numerical hydrodynamical models for Planetary Nebulae is reviewed. Since all of the numerical work is based on the interacting winds model, we start with a description of this model and give an overview of the early analytical…
We examine the possibility of detecting signatures of surviving Uranus-Neptune-like planets inside planetary nebulae. Planets that are not too close to the stars, orbital separation larger than about 5 AU, are likely to survive the entire…
We present the kinematics of a sample of bipolar planetary nebulae (PNe) which cover a wide range of observed morphologies and collimation degrees, from bipolar PNe with a marked equatorial ring and wide lobes to highly collimated objects.…
Context. Planetary nebulae are shells ejected by low- and intermediate-mass stars. The slow wind ejected by the asymptotic giant branch star is compressed by a fast stellar wind to produce an expanding gaseous shell surrounding a hot…
Considerable effort has been applied towards understanding the precise shaping mechanisms responsible for the diverse range of morphologies exhibited by planetary nebulae (PNe). A binary companion is increasingly gaining support as a…