A brief summary of some aspects of atomic physics theory useful for stellar atmospheres is given.

We present optical broad-band (UBVRI) aperture polarimetry of 52 post-AGB stars, selected from De Ruyter et al. (2006) and the Torun Catalog, based on the shape of their SED and near-infrared excess. We find 10 (19%) of the stars in our sample to have high polarization (P > 5%), 30 (56%) intermediate/low polarization (1% < P < 5%) and 13 (25%) very low (or non–polarized) polarization (P < 1%). Our observations show clear evidence of asymmetric circumstellar envelopes or equatorial density enhancement around post-AGB stars, probably formed at the beginning of the AGB phase. Some stars exhibit wavelength-independent polarization suggesting scattered light by large dust grains or free electrons (Thomson scattering), while others show wavelength-dependent polarization originated from scattering by small dust grains (Rayleigh scattering). Finally, we conclude that highly polarized sources (P > 3%), show systematically [12] − [25] > 1.5, J − H > 0.5 and J − K > 0.5, clearly separated from the group of RV Tauri stars, which are found to have very low polarization (P < 3%).

Since January 1st, 2010, the IAU (International Astronomical Union) fundamental celestialreference frame has been the 2nd International Celestial Reference Frame (ICRF2), which iscomposed of Very Long Baseline Interferometry (VLBI) positions for more than 3000extragalactic radio sources. This frame is constantly improving through joint efforts ofthe VLBI community. By surveying the whole sky up to magnitude 20, the European spaceastrometric mission Gaia will soon create its own celestial reference frame directly inthe optical domain and with many more sources. By 2015–2020, the two frames will thuscohabit and it will be important to align these to the highest accuracy for consistencybetween optical and radio positions. In this paper, we present the various observationalapproaches that are undertaken to improve the VLBI frame in the future. These includeextension to weaker sources for densification, extension to higher radio frequencies totake advantage of the more compact morphology of the sources at these frequencies, andfurther observations in the southern hemisphere for homogeneous sky coverage. We alsoelaborate on how such future radio frames should contribute to highly-precise alignmentbetween the VLBI and Gaia frames within the next decade.

This is an era of enormous opportunity in binary star research. The Leuven meeting provided an assessment of the broad scope of observational work, merits of the analysis methods, and connections with theory. Here I outline some of the issues related to spectroscopic, photometric, and high angular resolution observations of binary stars.

Photodissociation regions (PDRs) are gas phases in which far-ultraviolet radiation plays a significant role in the heating and/or chemistry (Tielens & Hollenbach 1985). X-ray dissociation regions (XDRs) are regions in which X-rays dominate the heating and/or chemistry (Moloney et al. 1996). Much progress has been mode in modeling PDRs (e.g., Röllig et al. 2007) and XDRs (e.g., Meijerink et al. 2007) and the models predict several line intensities and line ratios of atomic and molecular species that are good diagnostics for discriminating between the two. I will discuss the theoretical models in light of the most recent observations.

The Dome C high plateau is unique for coronagraphic observations: sky brightness is reduced, water vapour is low, seeing is excellent and continuity of observations on several weeks is possible. ESCAPE (the Extreme Solar Coronagraphy Antarctic Program Experiment) will perform 2-dimensional spectroscopy of the forbidden line of FeXIV at 530.285 nm: precise line profile analysis will allow the diagnostic of the nature of waves by simultaneous measurements of velocities and intensities in the corona. ESCAPE is proposed to Institut Paul-Emile Victor (IPEV) for a campaign in 2012–2013 at Dome C/Concordia since all subsystems are available in particular thanks to an ESA STARTIGER 2010 R&D “Toward a New Generation of Formation Flying Coronagraph”. Using state-of-the-art technologies developed for Space missions (a Three Mirrors Anastigmat telescope, the TMA, a 4 stages Liquid Crystal Tunable-filter Polarimeter, the LCTP) allows us to propose an automated Coronal Green Line full-field Polarimeter for unique observations (waves nature and intensity to address coronal heating) with the best possible performances on Earth and for preparing and testing the technologies for the next steps in Space. No other site would allow such coronagraphic performances (the sky brightness is a factor 2 to 4 better than in Hawaï) and with high spatial resolution (better than an arcsec is possible).

This paper provides a summary of binary star research conducted at the CHARA Array. The high angular resolution provided by the longest baselines of the interferometer can resolve binaries down to sub-milli-arcsecond separations. Combining the visual orbit of a binary with spectroscopic radial velocity variations of the components provides a measurement of the stellar masses and distance to the system. This paper provides an overview of interferometric methods used to resolve binaries and a table of orbits that have been resolved spatially using the CHARA Array. In addition to mapping the orbits of binary stars, the six telescopes in the array provide excellent coverage on the sky for studying the circumstellar environments within binary systems and investigating tidal effects within interacting binaries.

For space weather applications, it is important to understand filaments evolution and especially their eruptions associated with coronal mass ejections. In view of the cadence and continuity of SDO observations, AIA and HMI offer a unique tool for such a program. Because of the data volume and the requirement of short latency, only an automated detection can be worked out. We present a new method for the automated detection and tracking of filaments, based on the analysis of AIA 30.4 nm He ii images, with the capability to use also the magnetic field measured by HMI.

The brightest gamma-ray bursts (GRBs) would be detectable at very high redshifts and sooffer a probe of star-formation and galaxy evolution into the reionization era and evenbeyond. Localisation of their bright afterglows pinpoints their host galaxies, howeverfaint, and can give not only redshifts but also metallicity estimates, information on thepresence of dust and molecules, and HI column densities. Statistical samples ofwell-observed GRBs at high redshift may therefore reveal the evolution of the global starformation rate, chemical enrichment, far-ultraviolet escape fraction and the faint-end ofthe galaxy luminosity function; all of which are very difficult to establish viaconventional galaxy searches. To date, only a handful ofz > 6 GRBs have been identified, but their presenceat z > 8 begins to realise their potential assearchlights to illuminate the early Universe.

A large number of galactic and extragalactic sources exhibit a mid-IR spectrum that isdominated by PAH emission. Looking at these spectra in more details reveals a strongvariability in the shape/position of the observed features, depending on the observedsource, or even the region within a source. In this article, we present the results of ananalysis that has allowed us to decompose these spectra into components having a physicalmeaning. Most, if not all PAH dominated mid-IR spectra of HII regions, PDRs,protoplanetary disks, galaxies etc. can be fitted efficiently using a combination of thesecomponents. The results of these fits provide further insight in the composition of theemitting material and the local physical conditions. In the frame of the future IR spacemissions (JWST, SPICA), this approach can be very useful to probe the physical conditionsin distant galaxies.

The SPI spectrometer aboard of the INTEGRAL satellitehas released a map of the e+e− annihilation emission lineof unprecedented quality, showing that most of the photons arise from aregion coinciding with the stellar bulge of the Milky Way. Theimpressive intensity (≃ 10-3 photon cm-2 s-1) andmorphology (round and wide) of the emission is begging an explanation. Different classes of astrophysical objects could injectpositrons in the interstellar medium of the bulge, but the onlyacceptable ones should inject them at energies low enough to avoidexcessive bremsstrahlung emission in the soft gamma ray regime. Amongthe ~ MeV injectors, none seems generous enough to sustain the highlevel of annihilation observed. Even the most profuse candidate, namelythe β+ radioactivity of 56Co nuclei created and expelled inthe interstellar medium by explosive nucleosynthesis of type Iasupernovae, falls short explaining the phenomenon due to the smallfraction of positrons leaking out from the ejecta (≈3%),together with the low SNIa rate in the bulge (≈0.03 percentury). It is therefore worth exploring alternative solutions, as for instance,the idea that the source of the positrons is the annihilation of lightdark matter (LDM) particles of the kind recently proposed, totally independently, by Bœhm and Fayet. Assuming that LDM is the culprit, crucialconstraints on the characteristics (mass and annihilation cross-section)of the associated particle may be discussed, combining direct gammaray observations and models of the early Universe. In particular,the mass of the LDM particles should be significantly less than 100 MeV, so that the e+ and e− resulting from their annihilations do not radiate exceedingly through bremsstrahlung in the interstellar gas of thegalactic bulge.

In the Magellanic Clouds, the [CII]/CO and the [CII]/FIR ratios are much higher than seen in Milky Way star-forming regions. The enhanced relative strength of the [CII] line reflects the physical environment characterised by the low metallicities, dust abundances, and PAH abundances of the LMC, and especially the SMC.

In this lecture, the general properties of molecular clouds are presented, then the physics of the earliest stages of star formation is introduced thanks to a simplified stability analysis of these clouds. We later compare the outcomes of this analysis with observations of molecular clouds and point out the complex interplay of gravity, magnetic fields and turbulence necessary for the understanding of star formation processes, with a special emphasis on preliminary results from the recent Herschel Gould Belt survey.

Ground- and space-based observations have confirmed the presence of oscillatory motions in prominences and they have been interpreted in terms of magnetohydrodynamic (MHD) waves. This interpretation opens the door to perform prominence seismology, whose main aim is to determine physical parameters in magnetic and plasma structures (prominences) that are difficult to measure by direct means. Here, two prominence seismology applications are presented.

Directional information should play a significant role for a firm detection of the galactic dark matter. We developed a prototype three-dimensional gaseous tracking device for a direction-sensitive dark matter direct detection. We investigated the performance of the prototype detector and demonstrated a direction-sensitive dark matter search experiment in a surface laboratory. We set the first limit on the spin-dependent WIMP (Weakly Interacting Massive Particles)-proton cross s ection by a direction-sensitive method.

Among the various recombination schemes devised for nulling interferometry, one is to use the Achromatic Interfero Coronograph (AIC) which basically is a modified Michelson-Fourier interferometer made compact by cementing together optical components. The principle of this AIC is based on the focus-crossing property, from which a wave of light experiences an achromatic π phase shift when crossing a focus. Operated up to now only on a single telescope, this device is able to accomodate several beams for nulling. We describe the use of AIC as an interferometric nuller for a two-aperture interferometer.

Recent lyot coronagraphic performances achieved with adaptive optics (AO) instruments ADONIS/SHARPII, PUEO/KIR and NAOS/CONICA are presented and compared to detection limit predictions estimated with a simple analytic approach. The aim is to discuss and to determine the different observing limitations, to optimize the use of the instrument capabilities and to support the design of future instruments in the specific field of high contrast observations.

The papers in this volume represent a broad spectrum of observational, theoretical, and computational astrophysics, sharing as a unifying core the Disk-Halo Interaction in the Milky Way and other spiral galaxies. This topic covers a wide range of Galactic and extra-galactic research, built on a foundation of numerous and diverse physical processes. This summary groups the papers according to six themes, with some historical background and finally a look to the future. The final message is that the astrophysical techniques discussed and reviewed at this conference will grow over the next decade to answer even more fundamental questions about galaxy evolution and the history of the universe.

Some attempts to predict a very distant future of radio astronomy arepresented. It is not easy to foresee a list of the first priorityproblems which may appear, but the potential of research facilities ismore predictable. It is suggested that in addition to the “dedicatedfor radio astronomy” facilities, the instrumentation of radioastronomy may be extended greatly by integration with the nextgeneration “standard living” facilities, integrated viaPeople-to-People communications through global networks and byincorporating of the “natural facilities", such as gravitationallenses, maser amplification in the ISM etc. As an example of theextreme cases of the 109 m2 class of the new generation RadioTelescopes, utilization of the personal dipole-size communicationfacilitiy by a SKA-type instrument and an array formed by asteroids'first “Frehnel zones” will be mentioned. The latter radio astronomytool together with optical facilities will be extremely useful inexploration of the z>10 Universe. The reality of all predictionsdepend mostly on the way the Civilization will prefer to develop:“ahead, to HOMO SAPIENCE” or “back, to PRIMATES”.