By fitting the revised Hipparcos intermediate astrometric data (HIAD), we obtain thephotocentric orbital solutions of some single-lined spectroscopic binaries (SB1s) in the9th Catalogue of Orbits of Spectroscopic Binaries (SB9). For SB1s with relatively smallmagnitude difference between the two components, we find that the primary orbit is not agood approximation of the photocentric orbit in their orbit determination and suggest thatfuture spectroscopic observations and advanced spectral separation techniques should beapplied to these systems. In order to facilitate these future observations, we alsoestimate the full orbital solutions and provide the observational ephemerides. As anexample, we give the result for HIP 113860.

Large amounts of invisible matter have been discovered back in 1933 when the Swiss astronomer Fritz Zwicky measured for the first time the velocity dispersion of individual galaxies inside the Coma cluster. Since then, this pioneering observation has been confirmed on scales ranging from galactic radii to cosmological distances. The existence of the so–called astronomical dark matter is now well established. The puzzle lies in the fact that this essential component of the universe is not made of ordinary atoms and electrons. The astronomical dark matter is indeed non–baryonic. Its nature is still an unresolved issue. Many theoretical ideas and proposals have flourished in the past thirty years and yet none of them provides a definite answer. I have the challenging task to introduce the cohort of these dark matter candidates to you. They make up a bestiary of exotic species which have been recently proliferating. Instead of a liste à la Prévert, I will present a tentative classification of the various models.

ArTeMiS is a bolometer camera that will be installed at the APEX submillimeter telescope in Chile in 2010. This instrument will be a powerful tool for scientists with its three focal planes that will operate simultaneously in background limited conditions at 200, 350 and 450 microns (5760 pixels in total). A prototype called p-ArTeMiS has been tested at APEX in 2007 and thanks to its good performances, the team has been able to conduct scientific projects in star formation and on debris disks. This paper summarises the details of the ArTeMiS project, with a description of the detectors, the optics, the cryogenics and the electronics. We will also present the undergoing studies at CEA on detectors for the future submillimeter space missions.

We discuss the impact of the inclusionof both mass loss and rotation in massive star models at different metallicities.Rotation much improves the agreement between theory and observation. In particular rotational mixing allows to produce variations of the surface abundances already during the Main-Sequence phase. The changes of the surface abundances are more important when, for a given initial velocity, the initial mass increases, and/or the initial metallicity decreases. Alsothe observed high number of red supergiants at low metallicity can be accounted for by rotating stellar models, as well asthe observed variation of the number ratioof Wolf-Rayet to O-type stars as a function of the metallicity and the variation with themetallicity of the number ratio of type Ibc to type IIsupernovae. In all these questionsnon-rotating models give unsatisfactory fits. Rotating models can also give interestinginsights on questions as the origin of the Be stars, themechanisms responsible for thehuge mass loss rates undergone by the Luminous Blue Variables, the sources of primary nitrogen at low metallicity, the rotation rateof pulsars and the progenitors of the collapsars.

Assuming that the extended emission (EE) with broad dynamic range is a common property ofshort duration bursts, we propose a two-jet model which can describe both short mainepisode of hard spectra emission, specific for short bursts, and softer spectra EE by thedifferent off axis position of the observer. The model involves a short-duration jet,which is powered by heating due to νν̅ annihilation, and a long-lived Blandford–Znajek (BZ)jet with a significantly narrow opening angle. We also discuss observational tests oftwo-jet model.

We discuss the accuracy for the recovery of mass profiles in simulated dwarf galaxies. We also present cosmologically motivated, high resolution N-body models for two nearby dwarf galaxies: NGC 3109 and NGC 6822. The rotation curves in our models are measured using standard observational techniques, projecting velocities along the line of sight of an artificial observer and performing a tilted ring analysis. Our models reproduce the rotation curves of both galaxies, the disk surface brightness profiles as well as the profile of isophotal ellipticity and position angle. We show that non-circular motions combined with gas pressure support and projection effects systematically underestimate by up to 50% the rotation velocity of cold gas in the central ~1 kpc region, creating the illusion of a constant density core.

We present the results of an all sky survey for binary systems among the massive stars that we made with the HST Fine Guidance Sensors. The sample of 225 stars is comprised mainly of Galactic O- and B-type stars and Luminous Blue Variables, plus a few luminous stars in the LMC. The FGS TRANS mode observations are sensitive to detection of companions with an angular separation of 0.01–1 arcsec and brighter than △m = 5 mag. The FGS observations resolved 52 binary and 6 triple star systems and detected partially resolved binaries in 7 additional targets, yielding a companion detection frequency of 29%. We also gathered literature results on the numbers of close spectroscopic binaries and wider astrometric binaries among the sample. These results confirm the high multiplicity fraction. The period distribution is essentially flat in increments of log P, although there remains an observational gap in detections for periods of years and decades.

Stellar clusters are crucial in the study of a variety of topics including the star formation process, stellar nucleosynthesis and evolution, dynamical interaction among stars, or the assembly and evolution of galaxies. In particular, Open Clusters (OCs) have been widely used to constrain the formation and evolution of the Milky Way disc. They provide information about the chemical patterns and the existence of radial and vertical gradients or an age-metallicity relation. However, all these investigations are hampered by the fact that only a small fraction of clusters have been studied homogeneously. Galactic surveys performed from the ground such as the Apache Point Observatory Galactic Evolution Experiment (APOGEE), the Gaia-ESO Survey (GES), or the GALactic Archaeology with HERMES (GALAH) include OCs among their targets. OCs are also sampled from the space by the Gaia and Kepler missions.

The OCCASO goal is to derive abundances for more than 20 chemical species in at least 6 Red Clump stars in ∼30 Northern hemisphere OCs. In order to ensure the reliability of the derived chemical abundances, these are derived using different analysis techniques similar to what is being performed by GES.

One of the OCCASO requirements is the homogeneity between instruments, methods and model atmospheres used, and in the same scale than the GES-UVES abundances. For this reason we are performing different tests checking internal and external consistency. Derived stellar atmosphere parameters and Fe abundances will be published in the first data release scheduled for the first semester of 2015.

The online pdf of the poster with first results is available at https://gaia.ub.edu/Twiki/pub/GREATITNFC/ProgramFinalconference/poster_OCCASO.pdf.

We report an ultra-high-resolution simulation that follows evolution from the earliest stages of galaxy formation through the period of dynamical relaxation. The bubble structures of gas revealed in our simulation (<3×108 years) resemble closely the high-redshift Lyman α emitters (LAEs). After 109 years these bodies are dominated by stellar continuum radiation and look like the Lyman break galaxies (LBGs) known as the high-redshift star-forming galaxies at which point the abundance of elements appears to be solar. After 1.3×1010 years, these galaxies resemble present-day ellipticals. The comparisons of simulation results with the observations of elliptical galaxies allow us to conclude that LAEs and LBGs are infants of elliptical galaxies or bulge systems in the nearby universe.

This article is intended to be used as an introduction to the problem of protoplanetary dust aggregation. The basic concept of dust aggregation and its description by Smoluchowski's equation are presented. Analytic solutions to Smoluchowski's equation are explored which show some characteristics of the more general solutions, such as self-similarity and scaling behavior. The physics of dust aggregation is treated through interaction forces between the particles and empirical data on sticking efficiencies and particle morphologies in dust-dust collisions. Aggregate morphologies are described by the fractal concept, and its implications for collision cross sections and collision velocities are discussed. Theoretical and experimental work on collision-induced restructuring and fragmentation of fractal and non-fractal dust aggregates is presented. Finally, the latest modelling approaches for protoplanetary dust growth are discussed.

This is the manuscript of an "interactive seminar" from the programme of the EuroWinter School. These seminars were designed to illustrate areas of science that will be accessible to the VLTI and its first-generation instruments. This paper discusses the use of optical/IR interferometers to investigate the limb-darkening of stars, with particular emphasis on models with a one or two free parameters i.e. the kind of models that will be constrained by data from the first-generation VLTI. For this reason the paper is not a comprehensive treatment of limb-darkening measurement. Ideas from the introductory lectures of the School are illustrated here, using real data on a Mira variable star from the COAST interferometer.

The number of experiments on-board Lomonosov spacecraft are preparing now at SINP MSU inco-operation with other organisations. The main idea of Lomonosov mission is to studyextreme astrophysical phenomena, such as cosmic gamma-ray bursts and ultra-high energycosmic rays. These phenomena connect with processes occurred in very distant astrophysicalobjects of the Early Universe and give us information about first stages of Universeevolution. Thus, the Lomonosov mission scientific equipment includes several instrumentsfor gamma-ray burst observation in optics, ultra-violet, X-rays and gamma-rays and thewide aperture telescope for ultra-high energy particle study by detection of ionisationlight along its tracks in the atmosphere. The main parameters and a brief description ofthese instruments are presented.

CoRoT is the first instrument aiming at detecting exoplanets from space, using the transit method. It has been built in order to explore the domain of planets with orbital period less than three months, and size down to about two Earth radii. Successfully launched on the 27th of December 2006, the instrument started its science observations by the beginning of February 2007. The first detections show the capability of the instrument to enlarge the parameter space and to explore the transition regime between gaseous giant and terrestrial planets. Five new transiting giant planets discovered by CoRoT are fully characterized at the time of writing.

Recent ultra-high precision observations of eclipsing binaries, especially data acquired by the Kepler satellite, have made accurate light curve modelling increasingly challenging but also more rewarding. In this contribution, we discuss low-amplitude signals in light curves that can now be used to derive physical information about eclipsing binaries but that were unaccessible before the Kepler era. A notable example is the detection of Doppler beaming, which leads to an increase in flux when a star moves towards the satellite and a decrease in flux when it moves away. Similarly, Rømer delays, or light travel time effects, also have to taken into account when modelling the supreme quality data that is now available. The detection of offsets between primary and secondary eclipse phases in binaries with extreme mass ratios, and the observation of Rømer delays in the signals of pulsators in binary stars, have allowed us to determine the orbits of several binaries without the need for spectroscopy. A third example of a small-scale effect that has to be taken into account when modelling specific binary systems, are lensing effects. A new binary light curve modelling code, PHOEBE 2.0, that takes all these effect into account is currently being developed.

The dust in protoplanetary disks is influenced by many different processes. Among others, heating processes are the most important ones: they change not only the physical and chemical properties of dust particles, but also their emission spectra. In order to compare observed infrared spectra of young stellar systems with laboratory data of hot (up to 655°C) circumstellar dust analogues, we investigate materials, which are important constituents of dust in protoplanetary disks. We calculated the optical constants by means of a simple Lorentzian oscillator fit and applied them to simulations of small-particle emission spectra in order to compare our results with real astronomical spectra of AGB-stars and protoplanetary disks.

Observations of the interstellar medium (ISM) reveal its fractalstructure over a large range of scales. The quantitative description shows that the ISM consists mainly of surfaces, so that the stellar UV-radiation can deeply penetrate intothe ISM and in consequence dominates its physical and chemical conditions. Thus, the bulk of the ISM can be identified as photon dominated regions (PDRs). A simple model with the proper fractal characteristics is that of an ensemble of spherical clumps with a power-law mass spectrum and a power-law mass-size relation. Hence, we model the FIR line emission of the molecular gasby the integrated emission of such an ensemble, calculating the emission of individual clumps with the KOSMA-τ PDR code. This clumpy PDR-model, with observationally constrained parameters, is fitted to the CO, [C i], and [O i] emission along the Galactic plane as observed by the FIRAS instrument abord the COBE satellite. The FIR line intensity distribution with Galactic longitude is reproduced within factors of about 2. The predicted [C ii] 158 μm line intensity and FIR continuum emission also coincide with the observations.

There is a strong connection between the formation of a disk galaxy and the properties of the interstellar medium (ISM). Theoretical work has typically either focused on the cosmological buildup of a galaxy with a relatively crude model for the gas physics, or examined local processes in the ISM and ignored the global evolution of the galaxy itself. Here, I briefly review what has been learned from both of these approaches, and what can be done to bridge the gap between them. I argue that cosmological simulations need to learn from observational and theoretical work on local ISM properties and adopt more sophisticated models for the processes that they cannot resolve. Since the ISM is still incompletely understood, there are a number of reasonable approaches for these “subgrid" models, and I will discuss the strengths and limitations of each.

The Antarctic plateau has superb astronomical seeing above aturbulent boundary layer. This layer has a thickness of between tensof metres and a few hundred metres, depending on the site. We aredeveloping a sonic radar, SNODAR, to measure the turbulence in theboundary layer from 10 to 50 m, and, in particular, to measurethe height of the boundary layer to an accuracy of 1 m.Commercial sonic radars typically have a lower limit of about 10 m, and have 10 m range bins. The results from SNODAR shouldallow a confident assessment of the height at which one must mount atelescope in order to realise the superb free atmosphere seeing fromthe Antarctic plateau, which has been measured at Dome C to be 0.27arcsecs on average, and better than 0.15 arcsecs for 25% of thetime.


I present a personal summary of the first ARENA conference on the prospects of building large astronomical infrastructures at the Concordia station in Antarctica, and my view on our progress to date in achieving this goal. Inparticular, I discuss the basic scientific, technical, and political conditions which I believe must be satisfied in order to develop a world-classinternational astronomical facility at Concordia.


We focus our analysis on an event which occurred at the W-limb on May 30, 2003. The dynamical behavior of the filament, including damped oscillations, was investigated with the CDS and EIT (SoHO) experiments, as well as with Hα filtergrams (movies). The eruptive phase is analyzed taking into account the approximate phasing with other eruptive phenomena occurring at the same time or before, called homologous flares and eruptions.