We present the results from an optical monitoring campaign aimed at studying theafterglow properties of the short GRB 100816A. We implemented a new way of processing theSwift-BAT data, and based on it we reclassified this burst as short,discarding the initial classification as long. Observations were carried out mainly withthe GTC Telescope within the four following days after the burst to investigate theoptical photometry of its afterglow, and a year later to localize the host. We completedthe optical imaging with the 1.23 m and 3.5 m CAHA Telescopes. We built and fitted thenIR-optical SED for the characterization of the host. The best fit of the SED(χ2/d.o.f. = 1.656) obtained for assumed values of a solarmetallicity, and an extinction of AV = 0.2mag is obtained fora starburst galaxy with a dominant stellar population aging about 360 Myr.

Extra-planar gas in spiral galaxies can originate from disk-halo cycling driven by star formation in the disk or from infalling gas clouds. Studying the kinematics of halo gas can provide evidence for which scenario is more plausible. Edge-on galaxies provide a direct view of the extra-planar gas. We measure gas velocities from Hα emission as a function of height above the galactic disk for NGC 4244, which has a low star formation rate, and NGC 891, which has a high star formation rate. Using a multi-slit setup on the ARC 3.5 m telescope, we are able to measure velocities along 16 slits simultaneously. We compare our preliminary results to studies of HI velocities in these galaxies.

A brief description of the various types of variable stars occuring in the advanced stages of stellar evolution is given.This includes the Planetary Nebulae Nuclei variables (PNNV), the PG 1159 variables, the sdB pulsators and the DB and DA white dwarf pulsators. In this review, the emphasis is put on the importance of diffusion for eitherthe excitation mechanism or the properties of the oscillations.

γ-ray sources at synchrotron radiation facilities will provide unprecedented opportunities to investigate photonuclear reactions of astrophysical interest. I report recent research activities in Japan and call for an international collaboration to construct a photonuclear astrophysics database.

We present a brief discussion of the statistical surveys of HCN, HNC, HCO+ and HC3N that are used to model the extreme environments in the nuclei of starbursts and AGNs. Molecular studies are particularly useful for probing the deeply enshrouded dusty nuclei of luminous infrared galaxies. Here we present NGC 4418 as an example, one of the closest LIRG with high obscuration of the inner region. The interpretation of the observed line ratios require parallel development of theoretical chemical and radiative transport models.

Contrary to what is still often admitted when studying the chemical evolution of galaxies, the element abundances observed in stellar atmospheres are often not representative of the initial composition of the protostellar nebula. Element abundances may be altered during stellar evolution by atomic diffusion and/or accretion, if not by nuclear reactions. Atomic diffusion occurs in any type of stars, with time scales extremely different according to the macroscopic motions with which they have to compete. Accretion may occur in solar type stars during planetary formation, which seems to be a common process. Following the success of helioseismology, asteroseismology is now becoming a fundamental tool for penetrating the secrets of the internal structure of stars. In particular it may be used to derive their internal abundances compared to the observed ones. In the present paper, I focus on main-sequence stars. I first recall the situations where abundance stratification can act for exciting or stabilizing stellar oscillations, second I describe how seismic observations can be used to derive abundance gradients inside stars.

We explore the possibility of detecting and characterising the warp of the stellar disc of our Galaxy using the synthetic Gaia data and the UCAC4 proper motion catalogue. We develop a new kinematic model for the galactic warp. We generate random realisations of test particles which evolve in a realistic Galactic potential warped adiabatically to various final configurations. The Gaia selection function, its errors model and a realistic 3D extinction map are applied to mimic three tracer populations: OB, A and Red Clump stars. A family of Great Circle Cell Counts (GC3) methods is used. They are ideally suited to find the tilt and twist of a collection of rings, which allow us to detect and measure the warp parameters. Moreover, We look for the kinematic signature of the warp in the μb proper motions of stars as a function of galactic longitude. Using the UCAC4 proper motions, we do not obtain a similar trend as the one we expect from our warp model. We explore a possible source of this discrepancy in terms of systematics caused by a residual spin of the Hipparcos celestial reference frame (HCRF) with respect to the extra-galactic inertial one.

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.

Given the tendency of planets to form in multiples, and the observational evidence in support of the existence of potential planet-hosting stars in binaries or clusters, it is expected that extrasolar terrestrial planets are more likely to be found in multiple body systems. This paper discusses the prospects of the detection of terrestrial/habitable planets in multibody systems by presenting the results of a study of the long-term stability of these objects in systems with multiple giant planets (particularly those in eccentric and/or in mean-motion resonant orbits), systems with close-in Jupiter-like bodies, and systems of binary stars. The results of simulations show that while short-period terrestrial-class objects that are captured in near mean-motion resonances with migrating giant planets are potentially detectable via transit photometry or the measurement of the variations of the transit-timing due to their close-in Jovian-mass planetary companions, the prospect of the detection of habitable planets with the radial velocity technique is higher in systems with multiple giant planets outside the habitable zone and binary systems with moderately separated stellar companions.

Asteroseismology requires observables registered in stringent conditions: very high sensitivity, uninterrupted time series, long duration. These specifications then allow to study the details of the stellar interior structure.
Space-borne and ground-based asteroseismic projects are presented and compared. With CoRoT as a precursor, then Kepler and maybe Plato, the roadmap in space appears to be precisely designed. In parallel, ground-based projects are necessary to provide different and unique information on bright stars with Doppler measurements.
Dome C appears to be the ideal place for ground-based asteroseismic observations. The unequalled weather conditions yield a duty cycle comparable to space. Long time series (up to 3 months) will be possible, thanks to the long duration of the polar night.

We present a model for the dispersal of protoplanetary disks by winds from either the central star or the inner disk. These winds obliquely strike the flaring disk surface and strip away disk material by entraining it in an outward radial-moving flow at the disk-wind interface. This interface lies several disk scale heights above the mid plane. The disk dispersal time depends on the velocity at which disk material flows into the mixing layer. If this velocity is ~10% of the sound speed, the disk dispersal time at ~1–10 AU is ~5 Myr for a 0.01 M๏ disk around a solar mass star, with a spherical wind launched from the inner disk or central star with a typical mass loss rate of 10-8M๏yr-1 and terminal velocity of vw = 100 kms-1. We conclude that wind stripping is not a dominant disk dispersal mechanism compared with viscous accretion and photoevaporation. Nevertheless, wind stripping may affect the evolution of the intermediate disk regions.

In this contribution, I will focus on two nuclides, 26Al and19F whose origin has been uncertain for a long time and stillremains a matter of debate. I will present the contribution of ManuelForestini to the understanding of the origin of these nuclides, and inparticular to the description of their synthesis in asymptotic giant branchstars. I will also present an overview of the latest resultsconcerning 26Al and 19F and of the open questions stillto be answered.

We develop a simple method of dark energy reconstruction using a geometrical form of the luminosity-distance relation. In this method the FRW dynamical system with dark energy is reconstructed instead of the equation of state parameter. We give several examples which illustrate the usefulness of our method in fitting the redshift transition from the decelerating to accelerating phase as the value of the Hubble function at the transition.

The dynamics of stars and gas appear markedly different in flocculent, tidally induced and quasi-stationary spiral galaxies. Numerical simulations show that the gas and stars exhibit fairly chaotic dynamics during a tidal interaction, unlike the predictions of density wave theory. For a flocculent galaxy, the stars and gas tend to be situated in potential minima associated with the stellar distribution. I will demonstrate a possible observational test to distinguish between drivers of spiral structure by comparing the ages of stellar clusters, using the results of the simulations as an example.

With high resolution simulations, we are also starting to resolve giant molecular clouds, and can thus relate the properties of these clouds to the presence of spiral structure. Calculations so far suggest that spiral structure simply defines where the clouds form, rather than directly triggering star formation. In the last section of this review, I highlight recent efforts to produce synthetic HI and CO observations from numerical simulations.

The δ Scuti pulsators occupy a region in the Hertzsprung-Russell diagram where several physical processes occur: the subsurface convection layers change from being deep and vigorous to being shallow and ineffective to transport energy. This transition has a large impact not only on pulsational stability but also on stellar evolution, activity, transport of angular momentum, mixing processes, etc.. It is therefore of great interest to understand how exactly the stellar structure changes with increasing temperature and mass. Theoretical models (Houdek et al. 1999; Samadi et al. 2002) predicted that the convection in the outer layers of δ Scuti stars is still efficient enough to excite solar-like oscillations. The Kepler target, HD 187547 (a.k.a. Superstar), was the first δ Scuti star to suggest that solar-like oscillations are indeed present in this type of stars (Antoci et al. 2011). There were several reasons to conclude that HD 187547 is a δ Scuti/solar-like hybrid pulsator. (1) The peaks at high frequencies are modes of pulsations approximately equidistantly spaced, as expected for high radial order pressure modes; these peaks are not combination frequencies as it is sometimes observed in δ Scuti stars. (2) The opacity mechanism cannot excite a continuous frequency range as observed in HD 187547 (Pamyatnykh 2000). (3) The identification as an Am star consistent with the low v sini, makes it very unlikely to be a δ Scuti/roAp hybrid, because strong large-scale magnetic fields, a necessity for roAp pulsators, have never been detected in Am stars (Auriere et al. 2010). (4) Although a large number of Am stars are found in binary systems, we find no evidence in the observed spectra for a companion, i.e. no significant RV shift over 170 days can be detected and the absorption lines can perfectly be reproduced by assuming a slowly-rotating chemically peculiar Am star. This means that the peaks at high frequencies are unlikely to be from a companion, because such a star would be an A or F-type star and would be visible in the spectrum and this is not the case. (5) The large separation Δν, which is the frequency difference between consecutive radial orders of the same degree l, predicts the frequency of maximum power (νmax) to be exactly where the mode with the highest amplitude in the supposed stochastic region is observed. Note that the Δν and νmax scaling relation is valid only for stochastic oscillations (e.g. Huber et al. 2011). (6) The statistical properties (Chang & Gough 1998) of the modes interpreted to be solar-like were very similar to what is expected for stochastic signals in general.

Adaptive Optics Systems are now routinely operated on several4 meter class telescopes, allowing to achieve angular resolutionsdown to 70 msec in the near-infrared. Although these Systems have excellentperformances, their use for exploring the physics and structureof AGN is still limited for the following reasons: the limiting magnitudeof the wavefront sensor is too high, the sensitivity of infrareddetectors does not give access to medium/high spectral resolution spectroscopyand the angular resolution achieved does not always fit theapparent size of the physical components responsible for emission featuresclose to the central engine. The new generation of 8 — 10 m classtelescopes bring improvements in this matter. However, some interestingresults have been obtained so far with Adonis, the ESO La Sillaadaptive optics System on the 3.60 meter telescope, in the investigationof AGN structure. In particular, a prominent structure has beendetected in the central arcsec core of NGC 1068, which might featurethe dusty/molecular torus expected on theoretical grounds.

To determine the star formation histories of dwarf galaxies we use fossil methods. Compared to the color-magnitude diagrams analyzes, which are well tested and widely accepted, the studies of integrated spectra are still young. In order to assess their capabilities and limitations, we compare the results of three publicly available star formation recovery programs (StarLight, STECKMAP and ULySS).

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.

We demonstrate the important role of anisotropic neutrino radiation on the mechanism of core-collapse supernova explosions. Through a newparameter study with a fixed radiation field of neutrinos, we show thatprolate explosions caused by globally anisotropic neutrino radiationrepresent the most effective mechanism of increasing the explosionenergy when the total neutrino luminosity is given. This is suggestive ofthe fact that the expanding materials of SN 1987A have a prolategeometry.