Galactic Archaeology has recently been challenged by the fact that stars observed now in a certain location are not necessarily born there, but could have been kicked out from their birth places by different internal and/or external processes. We have made one of the first attempts to quantify how important stellar mixing could be in the case of our Galaxy, and how much of the original chemodynamical correlations would have been destroyed by such processes. Our unique approach has allowed us to conclude that although stellar mixing does take place in our Galaxy, many of the main relations between chemistry and age suggested by pure chemical evolution models are still generally valid. However, stringent constraints can be obtained only when stellar ages will be known for a large number of field stars. This is certainly one of the goals of Gaia, but in the meantime it has been shown that Asteroseismology can also provide a way to estimate ages of giants, even at large distances from the Sun. Here we present the first results obtained with a sample of CoRoT stars that have APOGEE spectra, in the framework of the CoRoGEE collaboration. The results coming from this still very recent approach (i.e. asteroseismology of Galactic populations) reveals that we might be on the right track in terms of quantifying radial mixing, but these results also suggest the chemical enrichment of the Galactic disk(s) to have been more complex than previously envisaged. Intriguingly, we find that the use of [α/Fe]-ratios as proxy for age, although generally valid, breaks down for some stars.

In this paper we present a method for hyper-spectral image restoration for integral field spectrographs (IFS) data. We specifically address two topics: (i) the design of a fast approximation of spectrally varying operators and (ii) the comparison between two kind of regularization functions: quadratic and spatial sparsity functions. We illustrate this method with simulations coming from the Multi Unit Spectroscopic Explorer (MUSE) instrument. It shows the clear increase of the spatial resolution provided by our method as well as its denoising capability.

SIAMOIS is a project devoted to ground-based asteroseismology,involving a small collector and an instrument to be installed at the Dome C Concordia station in Antarctica. After the space project CoRoT, SIAMOIS willprovide unique Doppler information on G and K type bright stars on the main sequence. Spectrometric observations with SIAMOIS will be able to detect oscillation modes that cannot beanalyzed in photometry, and will be less affected by stellaractivity noise.The SIAMOIS concept is based on Fourier Transform interferometry.Such a principle leads to a small instrument designed anddeveloped for the harsh conditions in Antarctica. The instrumentwill be fully automatic, with no moving parts, and a very simpleinitial set up at Dome C.Dome C appears to be the ideal place for ground-basedasteroseismic observations. The unequalled weather conditionsyield a duty cycle as high as 90% over 3 months, as was observedduring the 2006 wintering. This high duty cycle, a crucial pointfor asteroseismology, is comparable to the best space-basedobservations. Long time series (up to 3 months) will be possible,thanks to the long duration of the polar night.SIAMOIS can be seen as one of the very first astronomicalprojects to be conducted at Dome C. Its scientific programme will take full advantage of the unique quality of this site, and will constitute a necessary first step in preparation of future more ambitious programmes requiring more sophisticated instrumentation and larger collectors.


We have begun a general high resolution spectroscopic survey of the entire class of roAp stars to study systematics of the pulsations for the class, and to make detailed studies of individual stars. We have high spectral resolution (R ~ 110 000), high time resolution VLT UVES data for 16 of the 35 known members of the class, two of which were discovered during this survey. We show here some examples of studies of pulsation amplitude and phase as a function of line depth in Hα and in the 6145 Å line of Nd iii. The two of these lines together give a nearly continuous map of pulsation amplitude and phase as a function of optical depth from about -5 ≤ log τ5000 ≤ -2, or even higher. Our results for these lines and those of Fe support studies showing settling of Fe and levitation of Nd. The pulsation behaviour provides an independent constraint on atmospheric structure and abundance distribution in roAp stars, hence is important in tests of radiative diffusion calculations.

In January 2005, members of a Chinese expedition team were the first humans to visit Dome A on the Antarctic plateau, a site predicted to be one of the very best astronomical sites on earth.
In 2006, the Chinese Center for Antarctic Astronomy (CCAA) was founded to promote the development of astronomy in Antarctica, especially at Dome A. CCAA has since taken part in two traverses to Dome A, organized by the Polar Research Institute of China (PRIC), in the austral summers of 2007/2008 and 2008/2009. These traverses resulted in the installation of many site-testing and science instruments, supported by the PLATO observatory. The Chinese Small Telescope ARray (CSTAR) has produced excellent results from Dome A.
Our future plans include further site-testing work, and the following full-scale science instruments: three 0.5-m Antarctic Schmidt Telescopes (AST3), and a proposed 4-m telescope for wide-field infrared high spatial-resolution surveys. The first AST3 telescope is under construction and is scheduled for installation in 2011.

The diffuse interstellar bands (DIBs) have been known of since 1922, but their carriermolecules remain unidentified to this day. We present a brief history of DIB observations,followed by a list of constraints any suggested origin must face, and finally a preview ofcurrent research for ultraviolet DIBs using the Cosmic Origins Spectrographon the Hubble Space Telescope. We conclude that PAHs areconsistent with all the listed constraints, but that PAHs may not be the only molecularspecies responsible for the DIBs.

This paper first gives an introduction to the broad features of the Darwin mission of ESA and then describes in some detail the data processing that is necessary to detect planets and spectrally characterize them. The proposed data processing method is validated by means of simulated data.

The atmospheres of upper mainsequence chemically peculiar stars (ApBp stars) are known to be strongly affected by atomic diffusion. In recent years, both observations and models have shown that, as expected, the classical picture of abundance stratification is far too simple. A new generation of observational and modelling tools is appearing to take into account the complexity of the situation. In this talk, I will give an overview on recent results concerning the models for ApBp stars atmospheres. I will evaluate the two main approaches to estimate quantitatively the abundance stratifications: those using the so-called equilibrium hypothesis vs. those calculating time-dependent diffusion.

This proceeding is intended to be a first introduction to spectral methods. It is written around some simple problems that are solved explicitly and in details and that aim at demonstrating the power of those methods. The mathematical foundation of the spectral approximation is first introduced, based on the Gauss quadratures. The two usual basis of Legendre and Chebyshev polynomials are then presented. The next section is devoted to one dimensional equation solvers using only one domain. Three different methods are described. Techniques using several domains are shown in the last section of this paper and their various merits discussed.

Companions exert adverse effects on the relationships valid for Cepheids. Physicalcompanions may also cause observable effects (e.g., phase jump in thepulsation, slight excitation of non-radial modes). Many new binaries among Cepheids can berevealed by using radial velocity measurements to be made by Gaia and by derivingastrometric orbit from data to be obtained over the five years of the Gaia mission.

Cluster membership of Cepheids also facilitates the calibration of the period-luminosityrelationship independently of the pulsation. A brief summary on the membership of Cepheidsin clusters is also given.

Infrared absorption and emission features observed spectroscopically in our Galaxy allowto probe the composition of solid dust grains, their evolution and thus follow the cyclingof matter in the Galaxy. Many observables do reveal the presence of large amounts ofcarbonaceous particles in space, other than the PAH-like emission lines. The carbonaceousmaterials observed include amorphous carbons, diamondoids showing in emission for a fewspecific sources, and the recently detected fullerenes. An important hydrogenatedamorphous carbon component (HAC or a-C:H), traced by the 2940 cm-1 structuredabsorption feature is observed against Galactic background sources. Since the discovery ofthis feature in the early eighties (Allen 1981), theobservation of a-C:H has been extended to the mid-infrared by space observatories, givinginsight into additional associated features. They are also observed in external galaxies,showing the ubiquitous nature of these components. We will focus on astronomicalobservations of organic matter other than PAHs, amorphous carbons and associatedlaboratory dust analogues relevant to astrophysical applications.

ESO offers the opportunity to install a new (second generation)instrumentation on 8-m telescopes before 2010, for a wide community.We, as a consortium, argue that it is possible to develop a high contrastimager that will improve significantly or will complement current andforthcoming instruments. This project would benefit a interesting numberof astrophysical issues; it will also prepare later more ambitiousground-based imagers or space-based high contrast instruments.The limitations of the turbulence are severe and demand very performantadaptive optics. This critical question is addressed specifically.

The spectroscopic properties of protonated and deprotonated PAHs are investigated throughDensity Functional Theory (DFT) calculations, with reference to their potentialastrophysical significance. Attention is focussed on electronic and rotationalspectra.

The dynamical interactions that occur in newly formed planetary systems may reflect the conditions occurring in the protoplanetary disk out of which they formed. With this in mind, we explore the attainment and maintenance of orbital resonances by migrating planets in the terrestrial mass range. Migration time scales varying between ~106 yr and ~103 yr are considered. In the former case, for which the migration time is comparable to the lifetime of the protoplanetary gas disk, a 2:1 resonance may be formed. In the latter, relatively rapid migration regime commensurabilities of high degree such as 8:7 or 11:10 may be formed. However, in any one large-scale migration several different commensurabilities may be formed sequentially, each being associated with significant orbital evolution. We also use a simple analytic theory to develop conditions for first order commensurabilities to be formed. These depend on the degree of the commensurability, the imposed migration and circularization rates, and the planet mass ratios. These conditions are found to be consistent with the results of our simulations.

We address important mathematical properties of solutions of theMagnetic Doppler Imaging problem. We show that the underlyinginverse problem based on all 4 Stokes parameters is well-posed andthus has a unique solution. The only purpose of regularization is tosuppress instabilities induced by sparse sampling of phase and/orwavelength when dealing with practical data. Therefore, the finalsolution is stable with respect to the initial guess and is notaffected by the selection of a specific type of regularization.

The Herschel Dwarf Galaxy Survey investigates the interplay of star formation activity and the the metal-poor gas and dust of local universe dwarf galaxies using FIR and submillimetre imaging spectroscopic and photometric observations in the 50 to 550 μm window of the Herschel Space Observatory. The dust spectral-energy distributions are well constrained with the new Herschel and MIR Spitzer data. A submillimetre excess is often found in low metallicity galaxies, which, if tracing very cold dust, would highlight large dust masses not easily reconciled in some cases, given the low metallicities and expected gas-to-dust mass ratios. The galaxies are also mapped in the FIR fine-structure lines (63 and 145 μm OI, 158 μm CII, 122 and 205 μm NII, 88 μm OIII) probing the low density ionised gas, the HII regions and photodissociation regions. While still early in the mission we can already see, along with earlier studies, that line ratios in the metal-poor ISM differ remarkably from those in the metal-rich starburst environments. In dwarf galaxies, L[CII]/L(CO) (≥104) is at least an order of magnitude greater than in the most metal-rich starburst galaxies. The 88 μm [OIII] line usually dominates the FIR line emission over galaxy-wide scales, not the 158 μm [CII] line which is the dominant FIR cooling line in metal-rich galaxies. All of the FIR lines together can contribute 1% to 2% of the LTIR. The Herschel Dwarf Galaxy survey will provide statistical information on the nature of the dust and gas in low metallicity galaxies and place constraints on chemical evolution models of galaxies.

I address the problem of estimating stellar parameters using asteroseismic data. In particular I focus on the biases introduced the differences existing between observed and theoretical oscillation frequencies introduced by a poor modelling of near-surface layers. I review some methods to evaluate this shift and discuss briefly some studies trying to take into account this effect while estimating stellar parameters.

We report on a long-term monitoring of the cool supergiant Betelgeuse, using the NARVAL and ESPaDOnS high-resolution spectropolarimeters, respectively installed at Telescope Bernard Lyot (Pic du Midi Observatory, France) and at the Canada-France-Hawaii Telescope (Mauna Kea Observatory, Hawaii). The data set, constituted of circularly polarized (Stokes V) and intensity (Stokes I) spectra, was collected between 2010 and 2012. We investigate here the temporal evolution of magnetic field, convection and temperature at photospheric level, using simultaneous measurements of the longitudinal magnetic field component, the core emission of the Ca II infrared triplet, the line-depth ratio of selected photospheric lines and the radial velocity of the star.

GAIA spectroscopic and radial velocity performances are reviewed onthe base of ground-based test observations and simulations. Theprospects for accurate analysis of stellar atmospheres (temperature,gravity, chemical abundances, rotation, peculiarities) and preciseradial velocities (single stars, binaries, pulsating stars) arecolourful provided the spectral dispersion is high enough. A higherdispersions also favors a given precision of radial velocities to bereached at fainter magnitudes: for example, with current parametersfor GAIA spectrograph, a 1 km s-1 accuracy on individual epochRVs of a K0 star is reached at V~13.0 mag with 0.25 Å/pixdispersion spectra, at V~10.3 mag for 0.5 Å/pix, andV~6.7 mag for 1 Å/pix. GAIA radial velocities for singlestars can match the ~0.5km s-1 mean accuracy oftangential motions at V=15 mag, provided the observations areperformed at a dispersion not less than 0.5 Å/pix.