As of today more than 30 planetary systems have been discovered in binary stars. In all cases the configuration is circumstellar, where the planets orbit around one of the stars. The formation process of planets in binary stars is more difficult than around single stars due to the gravitational action of the companion. An overview of the research done in this field will be given. The dynamical influence that a secondary companion has on a circumstellar disk, and how this affects the planet formation process in this challenging environment will be summarized. Finally, new fully hydrodynamical simulations of protoplanets embedded in disks residing in a binary star will be presented. Applications with respect to the planet orbiting the primary in the system γ Cephei will be presented.

Traditionally, the study of the structural parameters of galaxies have been used to understand the bulge formation processes. However, one piece lost in this study is the three-dimensional shape of the bulges. In this work, the structural parameters of a magnitude-limited sample of 148 unbarred S0-Sb galaxies were derived to study the correlations between bulge and disk parameters as well as the probability distribution function (PDF) of the intrinsic equatorial ellipticity of bulges. A new algorithm (GASP-2D) was used to perform the bidimensional bulge-disk decomposition of J-band galaxy images extracted from the archive of the 2MASS survey. The PDF of intrinsic ellipticities was derived from the distribution of the observed ellipticities of bulges and misalignments between bulges and disks. About 80% of bulges in S0-Sb galaxies are not oblate but triaxial ellipsoids. Their mean axial ratio in the equatorial plane is 〈B/A〉=0.85. There is not significant dependence of their PDF on morphology, light concentration, and luminosity. The scenarios in which bulges assembled from mergers and/or grew over long times through disk secular evolution have to be tested against the derived PDF of bulge intrinsic ellipticities.

Magnetohydrodynamic turbulence has been proposed as a mechanism for the heating of coronal active regions, and has therefore been actively investigated in recent years. According to this scenario, a turbulent regime is driven by footpoint motions. The energy being pumped this way into active region loops, is efficiently transferred to small scales due to a direct energy cascade. The ensuing generation of fine scale structures, which is a natural outcome of turbulent regimes, helps to enhance the dissipation of either waves or DC currents.

We present an updated overview of recent results on turbulent coronal heating. To illustrate this theoretical scenario, we simulate the internal dynamics of a coronal loop within the reduced MHD approximation. The application of a stationary velocity field at the photospheric boundary leads to a turbulent stationary regime after several photospheric turnover times. This regime is characterized by a broadband power spectrum and energy dissipation rate levels compatible with the heating requirements of active region loops. Also, the energy dissipation rate displays a complex superposition of impulsive events, which we associate to the so-called nanoflares. A statistical analysis yields a power law distribution as a function of their energies, which is consistent with those obtained from observations. We also study the distributions of peak dissipation rate and duration of these events.

The faintest and darkest galaxies that we know of today are the dwarf spheroidal (dSph) galaxies. They appear to be plausible counterparts of cosmologically predicted small subhalos though their numbers do not (yet?) suffice to resolve the substructure crisis. Their mass-to-light ratios may go up to 1000 for the faintest objects, and their total masses are of the order of a few 106 to 107 M⊙. Though most dSphs are dominated by old populations, they all show extended and presumably slow star formation histories with considerable enrichment. While environment has certainly affected their evolution, as evidenced by the morphology-gas-distance relations, intrinsic properties such as their (initial) baryon content may also have played a major role. The complexity and diversity of their star formation histories is surprising, and there are no obvious evolutionary connections to dwarf irregulars.

This symposium was characterized by an intense exchange of new information and by lively discussions on many aspects of the formation and early evolution of low-mass stars. The observational data presented at this meeting, obtained in spectral regions ranging from X-rays to submm waves, were found to be remarkably consistent with the current magnetospheric disc-accretion paradigm for young stellar objects. But there remain open questions, and a full understanding of the star-formation process will require much additional work.

Division VI gathers astronomers studying the diffuse matter in space between stars, ranging from primordial intergalactic clouds, via dust and neutral and ionized gas in galaxies, to the densest molecular clouds and the processes by which stars are formed.

We present the results of a survey of N-body simulations aimed at exploring the implications of primordial mass segregation on the dynamical evolution of star clusters. We show that, in a mass-segregated cluster, the effect of early mass loss due to stellar evolution is, in general, more destructive than for an unsegregated cluster with the same density profile and leads to shorter lifetimes, a faster initial evolution toward less concentrated structure and flattening of the stellar initial mass function.

The occultation of a 9.1 magnitude star by asteroid (22) Kalliope and its satellite Linus was successfully observed in Japan in 2006 November 7.826 UT. This was the first definite observation of an occultation of a satellite of an asteroid that was discovered previously by other means. As a result the position of the satellite relative to Kalliope was obtained to be d = 0.246 ± 0.011 (arcsec), and P = 313.8 ± 2.7 (deg), where d is the angular distance and P is the position angle. The derived size for Kalliope is (209 ± 40)km × (136 ± 26)km (with the major axis in position angle of (8 ± 17) deg), and that for Linus is (33 ± 3) km. From the observations, the occulted star is also found to be a close double star whose separation is about 0.7 mas in position angle of about 300 deg, and the magnitudes of the components are found to be almost the same (~9.9 mag).

Massive stars inject energy into the surrounding medium and form shell structures. Bubbles are blown by fast stellar winds from individual massive stars, while superbubbles are blown by fast stellar winds and supernova explosions from groups of massive stars. Bubbles and superbubbles share a similar overall structure: a swept-up dense shell with an interior filled by low-density hot gas. Physical properties of a bubble/superbubble can be affected by magnetic field, thermal conduction, turbulent mixing, inhomogeneous ambient medium, etc. I will review recent progresses on observations and compare them to theoretical expectations for (1) swept-up dense shells, (2) hot interiors, and (3) interface between a dense shell and its interior hot gas.

We have used the VLBA to measure the annual parallax of the H2O masers in the star-forming region IRAS 00420+5530 (l=122.0°, b= -7.1°). This measurement yields a direct distance estimate of 2.17±0.05kpc, which disagrees substantially with most other published estimates (a range from 1.7 to 7.7kpc). This distance is consistent with recent parallax-based distances reported for W3(OH) (Xu et al. 2006, Hachisuka et al. 2006), lending additional support to the conclusion that the Perseus Spiral Arm of the Milky Way is a factor of at least two closer than kinematic distance estimates imply at galactic longitude ~130 degrees.

The nature of the dwarf galaxy population as a function of location in the cluster and within different environments is investigated. We have previously described the results of a search for low surface brightness objects in data drawn from an East-West strip of the Virgo cluster (Sabatini et al(2004)) and have compared this to a large area strip outside of the cluster (Roberts et al (2004)). In this talk I compare the East-West data (sampling sub-cluster A and outward) to new data along a North-South cluster strip that samples a different region (part of sub-cluster A, and the N, M clouds) and with data obtained for the Ursa Major cluster and fields around the spiral galaxy M101. The sample of dwarf galaxies in different environments is obtained from uniform datasets that reach central surface brightness values of 26 B mag/arcsec2 and an apparent B magnitude of 21 (MB =−10 for a Virgo Cluster distance of 16 Mpc). We discuss and interpret our results on the properties and distribution of dwarf low surface brightness galaxies in the context of variuos physical processes that are thought to act on galaxies as they form and evolve.

We summarize the results of two experiments to address important issues related to the correlation between planet frequencies and properties and the metallicity of the hosts. Our results can usefully inform formation, structural, and evolutionary models of gas giant planets.

The Exoplanet Search with PRIma (ESPRI) will use the PRIMA dual-feed astrometric capability on the Very Large Telescope Interferometer (VLTI) to perform astrometric detections of extra-solar planets. We present an overview of our data-reduction strategy for achieving 10-μarcsecond accuracy narrow-angle astrometry using the PRIMA instrument. We discuss the error budget for astrometric measurements, and those aspects of our strategy which are designed to minimise the astrometric measurement errors.

Two aspects of our recent N-body studies of star clusters are presented:

1. 1) What impact does mass segregation and selective mass loss have on integrated photometry?

2. 2) How well do results compare from N-body simulations using NBODY4 and STARLAB/KIRA?

Throughout their lives massive stars modify their environment through their ionizing photons and strong stellar winds. Here, I present coupled radiation-hydrodynamic calculations of the evolution of the bubbles and nebulae surrounding massive stars. The evolution is followed from the main sequence through the Wolf-Rayet stage and shows that structures are formed in the ISM out to some tens of parsecs radius. Closer to the star, instabilities lead to the breakup of swept-up wind shells. The photoevaporated flows from the resulting clumps interact with the stellar wind from the central star, which leads to the production of soft X-rays. I examine the consequences for the different observable structures at all time and size scales and evaluate the impact that the massive star has on its environment.

We report on absolute proper-motion measurements of H2O maser features in the NGC 281 West molecular cloud, located ~320 pc above the Galactic plane and associated with an HI loop extending from the Galactic plane. We conducted six-epoch phase-referencing observations of the maser source with VERA (VLBI Exploration of Radio Astrometry) over six months since May 2006. The H2O maser features are found to be systematically moving toward the southwest and further away from the Galactic plane with a vertical velocity of ~20–30 km s−1 at its estimated distance of 2.2–3.5 kpc. Our new results provide the most direct evidence that the gas in the NGC 281 region was blown out from the Galactic plane, most likely in a superbubble driven by multiple or sequential supernova explosions in the Galactic plane.

The bulges of spiral galaxies may be old, as in our Galaxy, or may possess younger stars, as evidenced in spectroscopic line strengths in some external bulges. Bulges look similar to elliptical galaxies, but their formation history is expected to differ due to the presence of the disc and different formation mechanisms. This project extends the numbers of high signal-to-noise, broad coverage spectra to a larger sample of bulges in order to test conflicting ideas about their age distributions. New Gemini long-slit observations will be used to derive stellar population ages and histories across 30 bulges. Here we present preliminary results from the sample.

Division VII provides a forum for astronomers studying our home galaxy, the Milky Way, which offers a unique laboratory for exploring the detailed structure of the stellar and gaseous components of galaxies and the process by which they form and evolve.

Alfvén waves can dissipate their energy by means of nonlinear mechanisms, and constitute good candidates to heat and maintain the solar corona to the observed few million degrees. Another appealing candidate is the nanoflare-reconnection heating, in which energy is released through many small magnetic reconnection events. Distinguishing the observational features of each mechanism is an extremely difficult task. On the other hand, observations have shown that energy release processes in the corona follow a power law distribution in frequency whose index may tell us whether small heating events contribute substantially to the heating or not. In this work we show a link between the power law index and the operating heating mechanism in a loop. We set up two coronal loop models: in the first model Alfvén waves created by footpoint shuffling nonlinearly convert to longitudinal modes which dissipate their energy through shocks; in the second model numerous heating events with nanoflare-like energies are input randomly along the loop, either distributed uniformly or concentrated at the footpoints. Both models are based on a 1.5-D MHD code. The obtained coronae differ in many aspects, for instance, in the simulated intensity profile that Hinode/XRT would observe. The intensity histograms display power law distributions whose indexes differ considerably. This number is found to be related to the distribution of the shocks along the loop. We thus test the observational signatures of the power law index as a diagnostic tool for the above heating mechanisms and the influence of the location of nanoflares.

The study of sub-structures in the stellar halo of the Milky Way has made a lot of progress in recent years, especially since surveys like the Sloan Digital Sky Survey became available. In this paper we focus on the newly discovered tidal tails of the Galactic globular cluster NGC 5466. By means of numerical simulations we reproduce the tidal tails, which are the longest tails associated with a globular cluster known (>45°) and hereby finding a possible progenitor of NGC 5466 and analyse its stability. We show that perigalactic passages are the dominant process in the slow dissolution of NGC 5466. Furthermore we use the position of the tails to verify the accuracy of the observationally determined proper motion. The proper motion has to be refined only slightly (within their stated error-margin) to match the location of the tidal tails.