We present our long-term monitoring, using both ground-based telescopes and the HST, of the expansion in the plane of the sky of the outflows from evolved stars. They include the PN M2–9 (suspected of hosting a symbiotic nucleus), the classical nova remnant GK Per, the symbiotic Miras R Aqr, Hen 2–147 and Hen 2–104, and the proto-PNe CRL 618, CRL 2688, and Hen 3–1475.

As a tool helping to interpret diffuse X-ray emission of PNe, and as a supplement to our RHD simulations, we have started to construct a grid of theoretical X-ray spectra of wind-blown bubbles with temperature and density profiles according to thermal conduction theory. We investigate how the X-ray spectra depend on chemical composition (e.g. H-rich vs. H-deficient) and how temperature and abundance determinations reflect gradients of temperature and chemical composition within the bubbles. These synthetic models shall allow to quickly perform detailed parameter studies without the need for dedicated hydrodynamical simulations. We report on ideas and goals.

NGC 5189 is a particularly interesting planetary nebula (PN) displaying multiple bipolar structures. This type of morphology is generally attributed to multiple mass loss events believed to originate from a precessing central source. In order to better understand this, once dubbed chaotic PN, we have investigated optical imaging combined with low- and high- resolution spectroscopic data to dissect its components. The imaging reveals three and possibly four well defined bipolar lobes showing a misalignment with respect to the central torus, although sharing the same geometric center. The high nitrogen levels detected in the elongated filaments/condensations surrounding the nebula and at the torus location highlight the presence of low ionization structures as well as the possible occurrence of shocks in the areas perturbed by large dynamical motions. Finally the kinematical study indicates moderate expansion velocities (35 km.s−1 in the western lobe, 33 km.s−1 in the central region and 44 km.s−1 in the eastern lobe). We also notice the asymmetry of the [NII] distribution and the velocities inside NGC 5189 between its North-West and South-East components.

Some developments of measurements of the weak stellar magnetic fields by the least square technique applied to spectropolarimetric data are proposed and used for the X-ray binary Cyg X-1 = HDE 226868 (the optical counterpart is an O 9.7 supergiant).

Polarimetry is a useful diagnostic of asymmetries in both circumstellar environments and binary star systems. Its sensitivity to asymmetries in systems means that it can help to uncover details about system orbital parameters, including providing information about the orbital inclination. Polarimetry can probe the circumstellar and/or circumbinary material as well. A number of significant results on binary systems have been produced by polarimetric studies. One might therefore expect that polarimetry could similarly play a useful role in studies of exoplanets, and a number of possible diagnostics for exoplanets have been proposed. However, the application of polarimetry to exoplanet research is only in preliminary stages, and the difficulties with applying the technique to exoplanets are non-trivial. This review will discuss the successes of polarimetry in analyzing binary systems, and consider the possibilities and challenges for extending similar analysis to exoplanet systems.

The long-period binary system AU Mon was photometrically observed on-board the CoRoT satellite in a continuous run of almost 60 days long which has covered almost 5 complete cycles. Unprecedented sub milimag precision of CoRoT photometry reveals all complexity of its light variations in this, still active mass-transfer binary system. We present images of an accretion disk reconstructed by eclipse mapping, and an optimization of intensity distribution along disk surface. Time resolution and accurate CoRoT photometric measurements allow precise location of spatial distribution of ‘hot’ spots on the disk, and tracing temporal changes in their activity. Clumpy disk structure is similar to those we detected early for another W Serpentis binary W Cru (Pavlovski, Burki & Mimica, 2006, A&A, 454, 855).

Limb-darkening is a fundamental constraint for modeling eclipsing binary and planetary transit light curves. As observations, for example from Kepler, CoRot, and Most, become more precise then a greater understanding of limb-darkening is necessary. However, limb-darkening is typically modeled as simple parameterizations fit to plane-parallel model stellar atmospheres that ignores stellar atmospheric extension. In this work, I compute linear, quadratic and four-parameter limb-darkening laws from grids of plane-parallel and spherically-symmetric model stellar atmospheres in a temperature and gravity range representing stars evolving on the Red Giant branch. The limb-darkening relations for each geometry are compared and are found to fit plane-parallel models much better than the spherically-symmetric models. Assuming that limb-darkening from spherically-symmetry model atmospheres are more physically representative of actual stellar limb-darkening than plane-parallel models, then these limb-darkening laws will not fit the limb of a stellar disk leading to errors in a light curve fit. This error will increase with a star's atmospheric extension.

Binary stars provide an excellent calibration of the success or otherwise of star formation simulations, since the reproduction of their statistical properties can be challenging. Here, I summarise the direction that the field has taken in recent years, with an emphasis on binary formation in the cluster context, and discuss which observational diagnostics are most ripe for meaningful theoretical comparison. I focus on two issues: the prediction of binary mass ratio distributions and the formation of the widest binaries in dissolving clusters, showing how in the latter case the incidence of ultra-wide pairs constrains the typical membership number of natal clusters to be of order a hundred. I end by drawing attention to recent works that include magnetic fields and which will set the direction of future research in this area.

The CoRoT and Kepler space missions have opened a new era in eclipsing binary research. While specifically designed for exoplanet search, they offer as by-products the discovery and monitoring of variable stars, in great majority eclipsing binaries (EB). The missions are therefore providing thousands of EB light curves of unprecedented accuracy (typically a few hundred parts per million, ppm), with regular sampling (from 1s to 29m), extending over time spans of months, and with a very high duty cycle (>90%).

Thanks to this excellent photometry, research topics as asteroseismology of EB components are quickly developing, and physical phenomena such as doppler boosting, theoretically predicted but extremely difficult to observe from the ground, have been unambiguously detected. We present the main properties of the Corot and Kepler EB samples and briefly review the highlights of the missions in this field.

In order to clarify the observed relation between the expansion velocity measured from lines of different ions and their ionization potential, we present kinematical data for several objects. We have measured radial velocities on ESO UVES high dispersion spectra to compare expansion velocities for a set of planetary nebulae.

The Magellanic Clouds are close enough to the Milky Way to provide an excellent environment in which to study extragalactic PNe. Most of these PNe are bright enough to be spectroscopically observed and spatially resolved. With the latest high resolution detectors on today's large telescopes it is even possible to directly observe a large number of central stars. Magellanic Cloud (MC) PNe provide several astrophysical benefits including low overall extinction and a good sample size covering a large range of dynamic evolutionary timescales while the known distances provide a direct estimation of luminosity and physical dimensions. Multi-wavelength surveys are revealing intriguing differences between MC and Galactic PNe.

Over the past 5 years there has been a substantial increase in the number of PNe discovered in the Large Magellanic Cloud (LMC) in particular. Deep surveys have allowed the faint end of the luminosity function to be investigated, finally providing a strong clue to its overall shape. In so doing, the surveys are approaching completeness, estimated at ~80% in the LMC (~120 deg2) and ~65% in the Small Magellanic Cloud (SMC) (~20 deg2).

The number of galaxies comprising the Local Group (LG) and its outskirts has been growing steadily over the past 5 years and now numbers 48. Most of the 7 newly discovered galaxies are dwarf spheroidal (dSph) in structure and range from 7.6 to 755 kpc from the Milky Way. Nonetheless, there are no published searches for PNe in any of these galaxies to date. Apart from the LMC and Milky Way, the number of PN discoveries has been very modest and only one additional LG galaxy has been surveyed for PNe over the past 5 years. This paper provides the number of Local Group PNe currently known and estimates each galaxy's total PN population.

We briefly discuss the method of population synthesis to calculate theoretical delay time distributions of Type Ia supernova progenitors. We also compare the results of different research groups and conclude that, although one of the main differences in the results for single degenerate progenitors is the retention efficiency with which accreted hydrogen is added to the white dwarf core, this alone cannot explain all the differences.

We have used the SuperCOSMOS Hα Survey to look for faint outer structures such as halos, ansae and jets around known planetary nebulae across 4000 square degrees of the southern Milky Way. Our search will contribute to a more accurate census of these features in the Galactic PN population. Candidate common-envelope PNe have also been identified on the basis of their microstructures. We also intend to determine more reliable distances for these PNe, which should allow a much better statistical basis for the post-AGB total mass budget. Our survey offers fresh scope to address this important issue.

The rates of SNe Ia for double-degenerate and single-degenerate scenarios are computed for the models of spiral and elliptical galaxies. The number of nuclear burning white dwarfs (NBWDs) is traced. The data favors the double-degenerate scenario and suggests a lower number of NBWDs per unit mass in ellipticals. Their lower average mass is one of the reasons for the difference in the number of supersoft X-ray sources observed in the galaxies of different types.

WEBDA (http://www.univie.ac.at/webda) is a site devoted to observational data of stellar clusters in the Milky Way and the Small Magellanic Cloud. It is intended to provide a reliable presentation of the available data and knowledge about these objects. The success of WEBDA is documented by its worldwide usage and the related acknowledgements in the literature: more than 650 refereed publications within the last twelve years acknowledged its use. It collects all published data for stars in open clusters that may be useful either to determine membership, or to study the stellar content and properties of the clusters.

The database content includes astrometric data in the form of coordinates, rectangular positions, and proper motions, photometric data in the major systems in which star clusters have been observed, but also spectroscopic data like spectral classification, radial velocities, and rotational velocities. It also contains miscellaneous types of supplementary data like membership probabilities, orbital elements of spectroscopic binaries, and periods for different kinds of variable stars as well as an extensive bibliography. Several powerful tools help to plot, query and extract the data, which can be directly retrieved via http. At the time of writing, about four million individual measurements have been included in the database. The Star Clusters Young & Old Newsletter (SCYON), a bi-monthly newsletter devoted to star cluster research with about 600 subscribers, is hosted in parallel with the database.

We present the current and upcoming new interface and tools, which are needed to visualize and analyze the increasing amount of data from all-sky surveys, and deeper investigations of binary systems, low mass dwarfs, as well as planet-hosting stars.

We build composite spectra at z ≤ 0.5 and z > 0.5 from the 3 year SuperNova Legacy Survey (SNLS) VLT spectral sample and study their differences around maximum light. We use 93 spectra near maximum of confirmed SNe Ia observed at the VLT between 2003 and 2006 as part of the 3 first years of operation of the SNLS. We find differences in the absorption depth of some intermediate mass elements (Ca ii, Si ii). Average stretches of observed distributions are 0.975 ± 0.016 and 0.983 ± 0.014 for the z ≤ 0.5 and z > 0.5 sample respectively. We use the A+B model of Scannapieco & Bildsten (2005) to interpret these results in terms of a possible demographic evolution.

The Be stars are still a big unknown in respect to the origin and geometry of the circumstellar disk around the star. Program shellspec is designed to solve the simple radiative transfer along the line of sight in three-dimensional moving media. Our goal was to develop an effective method to search in parameter space, which can allow us to find a good estimate of the physical parameters of the disk. We also present here our results for Be star 60 Cyg using the modified code.

Optical and near-infrared observations of novae give us useful information for understanding the diversity of nova eruptions. Classical nova V1723 Aql was discovered by F. Kabashima and K. Nishiyama on 2010 September 11. We have conducted photometric and spectroscopic observations of V1723 Aql in both optical and near-infrared (NIR) wavelength regions since its discovery. The V-band decline time by 2 mag after the maximum, t2, was ~12 d. The apparent Fe II emission lines were also seen in the optical spectra. The Rc- and Ic-band light curves exhibited rapid declines (0.16 mag d−1 in Rc) 20 days after the visual maximum, while the NIR (J, H, and Ks) showed slow decline rates (~0.07 mag d−1). This rapid reddening suggests that dust particles formed during the very early phase of the expansion in V1723 Aql.

Recent studies of the Algol-type binary RY Per presented strong evidence that there is an accretion disk around the primary in the system. We used new UBV photometry from Hvar Observatory and the BINSYN software package in order to determine the basic parameters of the disk. The search for the best parameter set was performed with a fully automated steepest descent method. The resulting disk is large and visible at all orbital phases. Somewhat surprising is the large mass transfer rate which should be tied with, currently unreported, secular period changes.

Production of multicharge ions due to generation of hot expanding plasma blobs, short-living “compound particles”, at high-velocity collisions between dust grains of a planetary nebula and dust particles of the interstellar medium is analytically considered. Dependence of the multiplicity of charge of produced ions on the relative velocity of colliding dust particles is determined.