The recent on-line availability of large-scale, wide-field surveys of the Galaxy and Magellanic Clouds in several optical and near/mid-infrared passbands has provided unprecedented opportunities to refine selection techniques and eliminate contaminants in PN surveys. This has been coupled with new surveys offering improved detection rates via higher sensitivity and resolution. This will permit more extreme ends of the PN luminosity function to be explored and enable studies of under represented PN evolutionary states. Known PNe in our Galaxy and LMC have thus been significantly increased over the last few years due primarily to the advent of narrow-band imaging in important nebula lines such as H$\alpha$, [O iii] and [S iii]. These PNe are generally of lower surface brightness, larger angular extent, in more obscured regions and in later stages of evolution than those in most previous surveys. A more representative PN population for in-depth study is now available, particularly in the LMC where the known distance adds considerable utility for derived PN parameters. Future prospects for Galactic and LMC PNe research are briefly highlighted.

The Local Group (LG) represents the best environment to study in detail the PN population in a large number of morphological types of galaxies. The closeness of the LG galaxies allows one to investigate the faintest side of the PN luminosity function and to detect PNe also in the less luminous galaxies, the dwarf galaxies, where a small number of them is expected.

A review of the results of the most recent imaging surveys in the LG is presented. Some applications of the surveys for PNe to the study of the star formation history of the host galaxies are analyzed. In addition, these new observational data are an invaluable resource for follow-up spectroscopy to derive the chemical properties of not only PNe, but also other important emission-line sources like HII regions. These are fundamental tools for the discussion of the chemical evolution of the host galaxies, mapping the history of their chemical enrichment at different epochs. The latest results on this subject are presented.

Historically, technological progress with detectors and instrumentation has been essential for advances in any field of observational astronomy, e.g. the advent of CCDs being crucial for high dynamic range imaging and quantitative spectroscopy of galactic PNe, faint object spectrophotometry for the discovery of extragalactic PNe to distances as far as 100 Mpc, etc. The emerging technique of integral field (“3D”) spectroscopy, which is being applied quite successfully to extragalactic astronomy, has unfortunately hardly been used so far for the study of PNe. However, 3D spectroscopy has an enormous potential for various observational problems, ranging from high spatial resolution emission line mapping in different wavelengths simultaneously, over extremely high sensitivity spectroscopy of low surface brightness objects like e.g. PN haloes, to accurate 3D spectrophotometry of extragalactic PNe, and many others. As an attempt to encourage PN researchers to make better use of these new opportunities, the presently existing suite of 3D instruments on 4–8m class telescopes is reviewed, highlighting some examples of successful 3D observations for the study of PNe.

The San Pedro Mártir Kinematic Catalogue of Planetary Nebulae aims at providing detailed kinematic information for galactic planetary nebulae (PNe) and bright PNe in the Local Group. The database provides long-slit, Echelle spectra and images where the location of the slits on the nebula are indicated. As a tool to help interpret the 2D line profiles or position-velocity data, an atlas of synthetic emission line spectra accompanies the Catalogue. The atlas has been produced with the code SHAPE and contains synthetic spectra for all the main morphological groups for a wide range of spatial orientations and slit locations over the nebula.

Distant planetary nebulae (PNe) are used to measure distances through the PN luminosity function, as kinematic tracers in determining the mass distribution in elliptical galaxies, and most recently, for measuring the kinematics of the diffuse stellar population in galaxy clusters. This article reviews the photometric and spectroscopic survey techniques that have been used to detect PNe beyond the Local Group, out to the Coma cluster at 100 Mpc distance. Contaminations by other emission sources and ways to overcome them will be discussed as well as some science highlights and future perspectives.

I review the progress in research on intracluster planetary nebulae over the last five years. Hundreds more intracluster planetary nebulae have been detected in the nearby Virgo and Fornax galaxy clusters, searches of several galaxy groups have been made, and intracluster planetary candidates have been detected in the distant Coma cluster. The first theoretical studies of intracluster planetaries have also been completed, studying their utility as tracers of the intracluster light as a whole, and also as individual objects.

From the results to date, it appears that intracluster planetaries are common in galaxy clusters (10-20% of the total amount of starlight), but thus far, none have been detected in galaxy groups, a result which currently is not well understood. Limited spectroscopic follow-up of intracluster planetaries in Virgo indicate that they have a complex velocity structure, in agreement with numerical models of intracluster light. Hydrodynamic simulations of individual intracluster planetaries predict that their morphology is significantly altered by their intracluster environment, but their emission-line properties appear to be unaffected.

In this talk, I describe methods for direct distance estimation to Planetary Nebulae (PNe). I review the foremost of these methods, the Expansion Parallax Distance, and present some recent results from this technique. In addition, I will discuss the major contributions to the systematic and random distance errors resulting from the method (including ionization front motions and deviations from spherical target morphologies), and show preliminary evidence quantifying these effects.

The local planetary nebula (PN) census is dominated by extremely evolved examples, and until recently, was incomplete. New discoveries from the AAO/UKST H$\alpha$ Survey and SHASSA, have partially remedied this problem. In addition, we find that some currently accepted nearby PNe are in fact Strömgren spheres in the ISM ionised by a hot white dwarf. Distance estimates for a robust sample of calibrating PNe from the literature, plus new distances for a number of highly evolved PNe, have allowed a new H$\alpha$ surface brightness – radius relationship to be devised as a useful distance indicator. It covers $>$6 dex in SB, and while the spread in SB is $\sim$1 dex at a given radius, optically thick (mainly bipolar and bipolar-core) PNe tend to populate the upper bound of the trend, while common-envelope PNe and very high-excitation PNe form a sharp lower boundary. Hence, distances can be estimated for all remaining local PNe, allowing the definition of a relatively complete census of PNe in the solar neighbourhood within 1.0 kpc. This provides a first look at the faint end of the PN luminosity function, and new estimates of the space density, scale height, total number, and birth rate of Galactic PNe.

Mass loss on the Asymptotic Giant Branch provides the origin of planetary nebulae. This paper reviews several relevant aspects of AGB evolution: pulsation properties, mass loss formalisms and time variable mass loss, evidence for asymmetries on the AGB, binarity, ISM interaction, and mass loss at low metallicity. There is growing evidence that mass loss on the AGB is already asymmetric, but with spherically symmetric velocity fields. The origin of the rings may be in pulsational instabilities causing mass-loss variations on time scales of centuries.

Multi-wavelength analyses of an increasing number of post-AGB stars reveal that they constitute a more inhomogeneous population of stars than previously thought. The new data collected in the last few years allow us to study these sources with unprecedented spatial resolution and to extend our spectroscopic knowledge in a systematic way to the infrared for the first time, where crucial information is contained on the chemical composition of the gas and dust in their circumstellar shells. The overall infrared properties derived from ISO and Spitzer data can be used to trace the mass loss history and the chemical evolution of the ejected material. The new results impose severe observational constraints on current nucleosynthesis models and suggest that the evolution is determined not only by the initial mass but also by the metallicity of the progenitor star. Post-AGB samples are likely to grow in the near future with the advent of new data from space facilities like Spitzer or Akari. Studies of post-AGB stars in the galactic halo, the Magellanic Clouds and other galaxies of the Local Group will certainly improve our knowledge on the evolutionary connections between AGB stars and PNe.

We present 1.6-4.7 $\mu$m images of PPNe and young PNe recently obtained with the Keck Adaptive Optics (AO) system. These observations provide higher angular resolution and probe deeper into the dusty envelopes of post-AGB objects than HST images and, therefore, show with unprecedented detail the morphology of these nebulae. Some objects have limb-brightened lobes displaying a remarkable point-like symmetry, which suggests the presence of underlying precessing jets that may be carving out the nebular lobes. Our images also show a very rich structure at the very small scale of $\sim$0.” 1, including jet-like features, arcs, searchlight beams, as well as faint, extended halos in a number of objects.

We report on the progress of our on-going campaign to monitor the evolution of the VLTP objects V4334 Sgr and V605 Aql, as well as the suspected (V)LTP object CK Vul. V4334 Sgr does not show signs of increased ionization compared to our previous observations in 2004. We obtained the first radio detection of V605 Aql, indicating a strong increase in radio flux since 1987. We also present the first radio detection of CK Vul and discuss the expansion of the material ejected during the 1670 event.

A review of the spectroscopic properties of post-AGB stars is presented.

We present the main results derived from a chemical abundance analysis carried out on a large sample of massive galactic O-rich AGB stars (M $>$ 3$-$4 M$_\odot$). Combining these results with previous studies made on a similar sample of luminous AGB stars belonging to the Magellanic Clouds we provide strong observational evidences that metallicity effects are playing a more important role than generally assumed in chemical evolution models. This concerns not only the onset of the so-called “hot bottom burning”, the efficiency of the third dredge-up and the s-process nucleosynthesis as derived from our optical observations, but also the dust production efficiency and the chemical properties of the dust grains in the shell, as inferred from the available infrared data. We find Li overabundances in the galactic stars studied, indicating that they are actually “hot bottom burning” AGB stars. Similar Li overabundances are also observed in the most luminous Magellanic Cloud AGB stars. However, the AGB stars in our galactic sample are not enriched in Zr, in contrast to what is observed in the Magellanic Clouds. In addition, many stars in the galactic sample appear heavily obscured in the optical, suggesting a much more efficient dust production and/or stronger mass loss rates which eventually can be translated into shorter AGB lifetimes.

I review some of the main nucleosynthesis processes in Asymptotic Giant Branch (AGB) Stars. These include production of $^{12}$C, $^{19}$F, $^{22}$Ne and $s$-elements in the He-rich layers above the degenerate C-O core, and modifications in the abundances of intermediate-mass elements up to Mg-Al, due to proton captures above the H-burning shell. Emphasis is put on the uncertainties still affecting the yields (especially mixing processes and mass loss rates) and on the possible role of planetary nebulae as a source of information on the evolution and nucleosynthesis of the AGB progenitors

We present preliminary results from a large-scale survey of the neutron(n)-capture elements Se and Kr in Galactic planetary nebulae (PNe). These elements may be produced in PN progenitors by s-process nucleosynthesis, and brought to the stellar envelope by third dredge-up (TDU). We have searched for [Kr iii] 2.199 and [Se iv] 2.287 $\mu$m in 120 PNe, and detected one or both lines in 79 objects, for a detection rate of 66%. In order to determine abundances of Se and Kr, we have added these elements to the atomic database of the photoionization code CLOUDY, and constructed a large grid of models to derive corrections for unobserved ionization stages. Se and Kr are enriched in $\sim$73% of the PNe in which they have been detected, and exhibit a wide range of abundances, from roughly solar to enriched by a factor of 10 or more. These enrichments are interpreted as evidence for the operation of the s-process and TDU in the progenitor stars. In line with theoretical expectations, Kr is more strongly enhanced than Se, and the abundances of both elements are correlated with the carbon abundance. Kr and Se are strongly enhanced in Type I PNe, which may be evidence for the operation of the $^{22}$Ne neutron source in intermediate-mass AGB stars. These results constitute the first broad characterization of s-process enrichments in PNe as a population, and reveal the impact of low- and intermediate-mass stars on the chemical evolution of trans-iron elements in the Galaxy.

The evolution of central stars of planetary nebulae can proceed in several distinct ways, either leading to H-deficiency or to H-normal surface composition. Several new simulations of the evolution channels that lead to H-deficiency are now available, mainly the born-again scenarios that are triggered by a He-shell flash during the hot pre-white dwarf evolution phase. A realistic AGB progenitor evolution is important for correct HRD tracks, that allow mass determinations. New hydrodynamic simulations of He-shell flash convection including cases with H-ingestion are now performed, and allow a determination of the convective extra-mixing efficiency. This has direct consequences for the intershell abundance distribution of AGB stars that can be observed in the H-deficient CSPN.

Only a handful of binary central stars of planetary nebulae (PNe) are known today, due to the difficulty of detecting their companions. Preliminary results from radial velocity surveys, however, seem to indicate that binarity plays a fundamental, rather than marginal role in the evolution of PNe and that the close binary fraction might be much larger than the currently known value of 10-15%. In this review, we list all the known binary central stars, giving an updated census of their numbers and selected characteristics. A review is also given of the techniques used to detect binaries as well as selected characteristics of related stellar classes which might provide constraints (or additional puzzles) to the theory of PN evolution. Finally, we will formulate the conjecture that all PNe derive from binary interactions and suggest that this is not inconsistent with our current knowledge.

The progress over the last years in modelling the atmospheres and winds of PN central stars is reviewed. We discuss the effect of the inclusion of the blanketing by millions of metal lines in NLTE on the diagnostics of photospheric and stellar wind lines, which can be used to determine stellar parameters such as effective temperature, gravity, radius, mass loss rate and distance. We also refer to recent work on the winds of massive O-type stars, which indicates that their winds are possibly inhomogeneous and clumped. We investigate implications from this work on the spectral diagnostics of PN central stars and introduce a method to determine wind clumping factors from the relative strengths of H$_{\alpha}$ and He II 4686. Based on new results we discuss the wind properties of CSPN.

According to previous spectral analyses of Wolf-Rayet type central stars, late [WC] subtypes show systematically higher carbon-to-helium abundance ratios than early [WC] subtypes. If this were true, it would rule out that these stars form an evolutionary sequence. However, due to the different parameter domains and diagnostic lines, one might suspect systematic errors being the source of this discrepancy. In an ongoing project we are therefore checking the [WC] analyses by means of the last generation of non-LTE models for expanding stellar atmospheres which account for line-blanketing and wind clumping. So far, the abundance discrepancy is not resolved. Further element abundances (H, N, Fe) are determined and compared with evolutionary predictions.