AMBER is the near I.R. focal instrument of the VLTI. It recombines 3 beams simultaneously and has spectral resolution capability allowing simultaneous spectrum, visibilities, differential visibilities, closure phase and differential phases measurements on the observed sources. We present here the general formalism used on AMBER in order to compute differential phases and differential visibilities, in complement to the article of Tatulli et al. (2006). We show that these differential observables have precisions close to the fundamental noises and we present an illustration of model-fitting using them on the binary star γ2 Velorum where we made a precise measurment of the astrometry of the 2 components (3.65±0.1 mas). 


Opening talk of the Conference and acknowledgments.

Polycyclic aromatic hydrocarbons are a class of molecules of broad interest that has longbeen explored by various spectroscopic techniques. The electronic spectroscopy of thesespecies is of particular interest since it provides a framework for the understanding ofthe electronic structure of large polyatomic molecules. Such studies also allow thesystematic investigation of electronic relaxation mechanisms in large molecules. In thisreview, we focus on the gas-phase experimental work on such systems and present the latestprogress. We also underline the challenges that remain to be tackled. A focus on theunderstanding of the electronic relaxation pathways at work in gas-phase PAHs will also bepresented, as well as their possible manifestation in space.

We analyze the long-term tidal evolution of a single-planet system through the use of numerical simulations and averaged equations giving the variations of the semi-major axis and eccentricity of the relative orbit. For different types of planets, we compute the variations due to the planetary and stellar tides. We then calculate the critical value of the eccentricity for which the stellar tide becomes dominant over the planetary tide. The timescales for orbital decay and circularization are also discussed and compared.

In this contribution, we summarize the recent progress made in recording laboratoryinfrared (IR) spectra of protonated polycyclic aromatic hydrocarbon molecules(H+PAH) in the gas phase. The IR spectra of a large variety ofH+PAH species ranging from benzene to coronene have been obtained by variousvariants of photodissociation spectroscopy. The employed techniques include single-photonIR photodissociation (IRPD) of tagged H+PAH ions and IR multiple-photondissociation (IRMPD) of bare H+PAH ions. The comparison of the laboratory IRspectra with astronomical spectra supports the hypothesis that H+PAH ions arepossible carriers of the unidentified IR emission (UIR) bands. Moreover, the spectraprovide detailed information about the geometric and electronic structure as well as thechemical reactivity and stability of these fundamental hydrocarbon ions.

Massive stars in their late stages of evolution as Red Supergiants experience mass loss.The resulting winds show various degrees of dynamical and chemical complexity and producemolecules and dust grains. This review summarises our knowledge of the molecular and dustcomponents of the wind of Red Supergiants, including VY CMa and Betelgeuse. We discuss thesynthesis of dust as a non equilibrium process in stellar winds, and present the currentknowledge of the chemistry involved in the formation of oxygen-rich dust such as silicatesand metal oxides.

Magnetic fields have been detected on stars across the H-R diagram and substellar objectseither directly by their effect on the formation of spectral lines, or through theactivity phenomena they power which can be observed across a large part of theelectromagnetic spectrum. Stars show a very wide variety of magnetic properties in termsof strength, geometry or variability. Cool stars generate their magnetic fields by dynamoeffect, and their properties appear to correlate – to some extent – with stellarparameters such as mass, rotation, and age. With the improvements of instrumentation anddata analysis techniques, magnetic fields can now be detected and studied down to thedomain of very-low-mass stars and brown dwarfs, triggering new theoretical works aimed, inparticular, at modelling dynamo action in these objects. After a brief discussion on theimportance of magnetic field in stellar physics, the basics of dynamo theory and magneticfield measurements are presented. The main results stemming from observational andtheoretical studies of magnetism are then detailed in two parts: the fully-convectivetransition, and the very-low mass stars and brown dwarfs domain.

Helioseismic inferences have demonstrated very clearly the importance ofincluding element diffusion and settling in solar modelling:models incorporating these processes are in substantially better agreement with the inferred solarsound speed than are models that neglect them.The remaining discrepancy between the models and the Sun has been taken asevidence for mixing in the region just beneath the convection zone.However, rather more serious discrepancies have resulted from a revisionof solar abundances, and no obvious solution to this problem has been foundso far.This perhaps demonstrates the danger of complacency when dealing with socomplex a thing as a star.Hydrodynamical instabilities are likely to play a more important role thanacknowledged in standard stellar modelling.An interesting example, if not relevant to modelling up to the present solarage, is the possible onset of semiconvective instability just beneath the convection zone, as first emphasized by Bahcall et al. (2001).


Observations of far-infrared (FIR) and submillimeter (SMM) polarizedemission are used to study magnetic fields and dust grains in denseregions on the interstellar medium (ISM). These observations placeconstraints on models of molecular clouds, star-formation, grainalignment mechanisms, and grain size, shape, and composition.
The FIR/SMM polarization is strongly dependent onwavelength. We have attributed this wavelength dependence to samplingdifferent grain populations at different temperatures. To date, mostobservations of polarized emission have been inthe densest regions of the ISM. Extending these observations toregions of the diffuse ISM, and to microwave frequencies, will provideadditional tests of grain and alignment models.
An understanding of polarized microwave emission from dust is key toan accurate measurement of the polarization of the cosmic microwavebackground. The microwave polarization spectrum will put limits on thecontributions to polarized emission from spinning dust and vibratingmagnetic dust.


Image reconstruction from interferometric data is an inverse problem. Owing to the sparse spatial frequency coverage of the data and to missing Fourier phase information, one has to take into account not only the data but also prior constraints. Image reconstruction then amounts to minimizing a joint criterion which is the sum of a likelihood term to enforce fidelity to the data and a regularization term to impose the priors. To implement strict constraints such as normalization and non-negativity, the minimization is performed on a feasible set. When the complex visibilities are available, image reconstruction is relatively easy as the joint criterion is convex and finding the solution is similar to a deconvolution problem. In optical interferometry, only the powerspectrum and the bispectrum can be measured and the joint criterion is highly multi-modal. The success of an image reconstruction algorithm then depends on the choice of the priors and on the ability of the optimization strategy to find a good solution among all the local minima.


In this talk we present the latest results from our ongoing project on geometro-thermodynamics (also known as information geometry of thermodynamics or Ruppeiner geometry) of dilaton BHs in 4D in both Einstein and string frames and a dyonic dilaton BH and at the end we report very briefly results from this approach to the 2D dilaton BHs.


The Low Frequency Array is a new radio telescope based on phased arrayprinciples that will operate at frequencies from 10–240 MHz. The vastimprovement in sensitivity and resolution over previous instrumentsthat have worked at these frequencies, together with the increasedflexibility that results from the phased array approach(multi-beaming, no moving parts) make LOFAR an extremely versatile andpowerful new instrument. We present some of the scientific drivers andgive an overview of the current design.


The hypothesis that polyaromatic molecules are the carriers of the infrared interstellaremission bands has spurred the laboratory spectroscopy of this class of molecules. Here wewill give an overview of the infrared spectroscopic methods that have been applied overthe past two decades to investigate the IR spectra of PAHs, their ions and relatedspecies.

Numerous hydrogenated molecules observed in comets and the interstellar medium presentnuclear spin isomers. The non-thermal ortho: para ratiosmeasured in space are believed to be of high diagnostic value, allowing remote measurementof physical conditions prevailing in the past, such as the initial temperature associatedwith a molecular formation or condensation. The lack of laboratory studies on interactionsat the gas-solid interface limits our current interpretation of observations. Recentprogress in nuclear spin conversion (NSC) dynamics are discussed in this paper. Results onwater and methane in cryogenic matrices illustrate the conversion mechanisms within thecondensed phase at very low temperatures. NSC of molecular hydrogen at the surface of 10 KAmorphous Solid Water (ASW) shows surface mediated conversion processes for molecularhydrogen. NSC involving molecular ices are discussed in the light of few recent studies,including UV photodesorption investigations.

Moderately close binaries are a special class of targets for planet searches. From a theoretical standpoint, their hospitality to giant planets is uncertain and debated. From an observational standpoint, many of these systems present technical difficulties for precise radial-velocity measurements and classical Doppler surveys avoid them accordingly. In spite of theseadverse factors, present data support the idea that giant planets residing in binary and hierarchical systems provide unique observational constraints on the processes of planet formation and evolution. The interest and the importance of including various types of binary stars in extrasolar planet studies have thus grown over time and significant efforts have recently been put into: (i) searching for stellar companions to the known planet-host stars using direct imaging, and (ii) extending Doppler planet searches to spectroscopic and moderately close visual binaries. In this contribution we review the observational progress made over the past few years in the detection andstudy of extrasolar planets in binary systems, putting special emphasis on the two developments mentioned above.

We present “A STEP”, a project dedicated to the search for planetarytransits from Antartica. The project consists of a fully automatic 40 cm telescope equipped with an 11-million-pixel CCD installed atDome C. The site offers crucial assets for a ground-based exoplanettransit search: uninterrupted phase coverage and excellentseeing. 
This system would be able to detect hot Jupiters transiting in frontof stars as faint as magnitude sixteen and could also detect smallerplanets in close-in period around brighter stars. Our estimations,based on results of previous surveys are an average of 6 detectionsper 60 days survey. Compared to existing surveys, this excellent yieldis due to the nearly-continuous phase coverage and excellent seiing.This short term project is meant to be a photometric qualifyer for thesite and the first stage of a massive detection campaign. A mid-termobjective of 1000 detections for 2012 could be achieved either with manysmall telescopes or with a large Schmidt telescope with a large fieldof view. 
The project is relatively simple and cost-effective, and has thedouble purpose of qualifying the site and obtaining first-classscientific results. Our team is already familiar with transitdetection with an automated telescope (BEST) and cold temperaturequalification.

This chapter is intended to provide a general presentation of the atomic andnuclear processes responsible for X-ray line and gamma-ray line emission invarious astrophysical environments. I consider line production from hotplasmas, from accelerated particle interactions, from the decay ofradioactive nuclei synthesized in stars and from positron annihilation.Spectroscopic properties of these emissions are discussed in the light ofthe detection capabilities of modern space instruments.

We discuss the physics and the evolution of a typical massive star passing through an evolutionary stage similar to that of Betelgeuse. After a brief introduction recalling various observed parameters of Betelgeuse, we discuss the Pre-Main-Sequence phase (PMS), the Main-Sequence (MS) phase, the physics governing the duration of the first crossing of the HR diagram, the red supergiant stage (RSG), the post-red supergiant phases and the final fate of solar metallicity stars with masses between 9 and 25 M⊙. We examine the impact of different initial rotation and of various prescriptions for the mass loss rates during the red supergiant phase. We show that, whatever the initial rotation rate (chosen between 0 and 0.7 × υcrit, υcrit being the surface equatorial velocity producing a centrifugal acceleration balancing exactly the gravity) and the mass loss rates during the RSG stage (varied between a standard value and 25 times that value), a 15 M⊙ star always ends its lifetime as a RSG and explodes as a type II-P or II-L supernova.

Angular momentum transport in accretion disk has been the focus of intense research in theoretical astrophysics for many decades. In the past twenty years, MHD turbulence driven by the magnetorotational instability has emerged as an efficient mechanism to achieve that goal. Yet, many questions and uncertainties remain, among which the saturation level of the turbulence. The consequences of the magnetorotational instability for planet formation models are still being investigated. This lecture, given in September 2012 at the school “Role and mechanisms of angular momentum transport in the formation and early evolution of stars” in Aussois (France), aims at introducing the historical developments, current status and outstanding questions related to the magnetorotational instability that are currently at the forefront of academic research.