Related papers: Identifying close binary central stars of PN with …
In this second paper on our variability survey of central stars of planetary nebulae (CSPNe) using ZTF, we report 11 long-timescale variables with variability timescales ranging from months to years. We also present preliminary analyses…
The Optical Gravitational Lensing Experiment (OGLE), originally designed to search for microlensing events, provides a rich and uniform data set suitable for studying the variability of certain types of objects. We used the OGLE data to…
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…
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…
Close binary systems undergoing mass transfer or common envelope interactions can account for the morphological properties of some planetary nebulae. The search for close binary companions in planetary nebulae is hindered by the difficulty…
The discrepancy between abundances computed using optical recombination lines (ORLs) and collisionally excited lines (CELs) is a major unresolved problem in nebular astrophysics. We show here that the largest abundance discrepancies are…
The Kepler K2 mission now makes it possible to find and study a wider variety of eclipsing binary stars than has been possible to-date, particularly long-period systems with narrow eclipses. Our aim is to characterise eclipsing binary stars…
We present the discovery of a 3h5m orbital-period binary star at the heart of the planetary nebula M 3-1 - the shortest period photometrically-variable central star known and second only to V458 Vul, in general. Combined modelling of light…
We present new imaging data and archival multiwavelength observations of the little studied emission nebula K 1-6 and its central star. Narrow-band images in H-alpha (+ [NII]) and [OIII] taken with the Faulkes Telescope North reveal a…
We report on a high-spatial-resolution survey for binary stars in the periphery of the Orion Nebula Cluster, at 5 - 15 arcmin (0.65 - 2 pc) from the cluster center. We observed 228 stars with adaptive optics systems, in order to find…
Planetary nebulae are one of the final stages in the evolution of low and intermediate mass stars. They occur in a variety of shapes. Older and fainter ones are generally more difficult to identify because of the lower surface brightness.…
We have analyzed Kepler light curves for 849 stars with T_eff < 5200 K from our Cycle 1 Guest Observer program. We identify six new eclipsing binaries, one of which has an orbital period of 29.91 d, and two of which are probably W UMa…
We present the first detailed spatio-kinematical analysis and modelling of the planetary nebula Shapley 1 (Sp 1), which is known to contain a close-binary central star system. Close-binary central stars have been identified as a likely…
The importance of long-period binaries on the formation and evolution of planetary nebulae is still rather poorly understood, in part due to the lack of central star systems known to comprise such long-period binaries. Here, we report on…
We present a detailed study of the stellar and orbital parameters of the post-common envelope binary central star of the planetary nebula Ou~5. Low-resolution spectra obtained during the primary eclipse -- to our knowledge the first…
We present a $\approx 11.5$ year adaptive optics (AO) study of stellar variability and search for eclipsing binaries in the central $\sim 0.4$ pc ($\sim 10''$) of the Milky Way nuclear star cluster. We measure the photometry of 563 stars…
The shaping of the nebula is currently one of the outstanding unsolved problems in planetary nebula (PN) research. Several mechanisms have been proposed, most of which require a binary companion. However, direct evidence for a binary…
While analysing the images of the IPHAS H$\alpha$ survey, we noticed that the central star of the candidate planetary nebula IPHASXJ211420.0+434136 (also named Ou5) was clearly variable. This is generally considered as an indication of…
A recent analysis of high precision photometry obtained using the Kepler spacecraft has revealed two surprising discoveries: (1) over 860 main sequence A-type stars -- approximately 40% of those identified in the Kepler field -- exhibit…
Despite years of effort, the impact of central star binarity on planetary nebula formation and shaping remains unclear. This is hampered by the fact that detecting central star binarity is inherently difficult, and requires very precise…