Related papers: The binary central stars of PNe with the shortest …
Double-close-binary quadruples (2+2 systems) are hierarchical systems of four stars where two short-period binary systems move around their common center of mass on a wider orbit. Using Gaia Early Data Release 3, we search for comoving…
Mid-IR observations of planetary nebulae (PNe) have revealed diffuse emission associated to their main nebular shells and outer envelopes or haloes. The interpretation of this emission is uncertain because the broad-band mid-IR images may…
In this brief invited review, I will attempt to summarise some of the key areas of interest in the study of central stars of planetary nebulae which (probably) won't be covered by other speakers' proceedings. The main focus will,…
Planetary nebulae (PNe) have the potential to revolutionize our understanding of extragalactic stellar populations. Indeed, in many systems, bright PNe are the only individual objects identifiable from the ground, and, even more often, they…
Planetary nebulae (PNe) are valuable spatial and kinematic tracers of nearby galaxies. In this mini-review, I focus on their role in tracing the halo and intra-cluster/intra-group light assembly in groups and clusters of galaxies within…
Planetary nebulae (PNe) are essential tracers of the kinematics of the diffuse halo and intracluster light where stellar spectroscopy is unfeasible, due to their strong emission lines. However, that is not all they can reveal about the…
We derive the stellar and circumstellar parameters of the Galactic compact planetary nebula Hen 2-90 with two models: the classical constant density nebula model where the emission (especially of the forbiden lines) is formed in a sphere or…
We consider the possibility of cluster membership for 13 planetary nebulae that are located in close proximity to open clusters lying in their lines of sight. The short lifetimes and low sample size of intermediate-mass planetary nebulae…
Planetary nebulae represent a potential late stage of stellar evolution, however the central stars (CSPNe) are relatively faint and therefore pertinent information is merely available for <20% of the Galactic sample. Consequently, the…
Close binary systems often show linear polarization varying over the binary period, usually attributed to light scattered from electrons in circumstellar clouds. One of the brightest close binary systems is Spica (Alpha Virginis) consisting…
The study of detached eclipsing binaries in open clusters can provide stringent tests of theoretical stellar evolutionary models, which must simultaneously fit the masses, radii, and luminosities of the eclipsing stars and the radiative…
We report results of an HST "snapshot" survey aimed at finding resolved binary companions of the central stars of Galactic planetary nebulae (PNe). Using WF/PC and WFPC2, we searched the fields of 113 PNe for stars whose close proximity to…
We present medium-resolution (R~700) near-infrared (lambda = 1 - 2.5 micron) spectra of a sample of planetary nebulae (PNe). A narrow slit was used which sampled discrete locations within the nebulae; observations were obtained at one or…
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…
We present the many evolutionary routes that progenitors of bipolar planetary nebulae (BPNe) can take. Overall, there are about a hundred qualitatively different evolutionary routes, hence about a hundred qualitatively different types of…
Planetary nebulae (PNe) are the only single stars in galaxies outside the Local Group that can be used as kinematic tracers of the diffuse light in the extended halo. Analysing their luminosity-specific number density across galaxies of…
We present surprising similarities between some bipolar planetary nebulae (PNe) and eruptive objects with peak luminosity between novae and supernovae. The later group is termed ILOT for intermediate luminosity optical transients (other…
Only four globular cluster planetary nebulae (GCPN) are known so far in the Milky Way. About 50 new globular clusters have been recently discovered towards the Galactic bulge. We present a search for planetary nebulae within 3 arcmin of the…
Once classified as an emission line source, the planetary nebula (PN) nature of the source Kn 26 has been only recently recognized in digital sky surveys. To investigate the spectral properties and spatio-kinematical structure of Kn 26, we…
Although no intermediate polar (IP) has been observed in recent years to descend into a state of low rate of mass transfer, there are candidate stars that appear to be already in intermediate and low states. V709 Cas is probably an…