The Franco-Algerian Monitor of Solar Images (MISOLFA) was developped in order to study the effect of optical turbulence on diameter measurements from ground-based solar observations. Some first results obtained with MISOLFA are presented.

Coronal “EIT wave” is a large-scale wavelike phenomenon propagating across the major part of the Sun. Debates are being continued regarding a more suitable name for it, its source driver, and its nature. “EIT waves” have been widely explained in terms of fast-mode waves, despite that the model contradicts with many observational features. Two-types of EUV waves were predicted 10 years ago. With the recent high-cadence observations, mainly from SDO/AIA telescope, more and more evidence has been revealed in favor of the two-wave model. In this paper, after summarizing different names used for EIT waves in the literature, we show how the community are getting close to reaching a consensus on the nature of EIT waves.

Magnetic field are ubiquitous to young and mature low-mass stars, and can potentially impact their formation, their evolution and their internal structure; yet the physical processes that succeed at amplifying and sustaining these fields (called dynamo processes), like those capable of changing the fate of the host stars (and in particular their rotation rates), are still somewhat enigmatic. Although theoretical modelling and numerical simulations (e.g., of stellar dynamo action and magnetospheric accretion processes) showed breathtaking progress in the last decade, they are not yet in the state of accurately predicting the various magnetic topologies that different low-mass stars can generate nor the impact such fields can have on stellar formation.

Thanks to the advent of new-generation instruments, spectropolarimetric observations coupled to tomographic techniques can now reveal the large-scale magnetic topologies of both young and mature low-mass stars, and in particular their poloidal and toroidal components. More specifically, one can now investigate magnetic topologies of cool dwarfs, all the way from the brown dwarf threshold (spectral type M8) where stars are fully convective up to the limit beyond which outer convective zones get vanishingly small (spectral type F5); one can also explore the magnetic topologies of young low-mass stars that are still accreting mass from their circumstellar disc (i.e., the classical T Tauri stars) and study how such fields can impact mass accretion processes from the surrounding discs.

We review herein the latest observational advances in this field, showing in particular that large-scale magnetic topologies of low-mass stars and protostars can drastically vary with mass and rotation rate, and discuss their implications for our understanding of dynamo processes, stellar formation and stellar evolution.

This contribution describes our solar project at theAntarctic sites of Baia Terranova, South Pole and Dome-C. The project is based on a multi-level helioseismology analysis, aimed to study, for the first time, the local properties of the solar atmosphere. In addition, we plan to detect the presence of Alfvèn waves in and around the active regions, as an energy transfer vehicle from sunspots towards the corona. The technology used is the well known compact, stable, relatively unexpensive and still improving MOF (Magneto-Optical Filter).

Two-dimensional models of rapidly rotating stars are already unavoidable for the interpretation of interferometric or asteroseismic data of this kind of stars. When combined with time evolution, they will allow the including of a more accurate physics for the computation of element transport and the determination of surface abundances. In addition, modeling the evolution of rotation will improve gyrochronology. Presently, two-dimensional ESTER models predict the structure and the large-scale flows (differential rotation and meridional circulation) of stars with mass larger than 1.7 M⊙ at any rotation rate. Main sequence evolution can be mimicked by varying the hydrogen content of the convective core. Models have been successfully tested on half a dozen of nearby fast rotating stars observed with optical or infra-red interferometers. They are now the right tool to investigate the oscillation spectrum of early-type fast rotators.

We first review the nonrelativistic Lagrangian theory as a framework for the MOND equation. Obstructions to a relativistic version of it are discussed leading up to TeVeS, a relativistic tensor-vector-scalar field theory which displays both MOND and Newtonian limits. The whys for its particular structure are discussed and its achievements so far are summarized.

The Penn State/Toruń Centre for Astronomy Search for Planets Around Evolved Stars is a high-accuracy radial velocity (RV) survey aiming at planet detection around giant stars. It is based on observations obtained with the 9.2 m Hobby-Eberly Telescope. As proper interpretation of high accuracy RV data for red giants requires complete spectral analysis of targets we perform spectral modeling of all stars included in the survey. Typically, rotation velocities and metallicities are determined in addition to stellar luminosities and temperatures, which allows us to estimate stellar ages and masses. Here we present preliminary results of metallicity studies in our sample. We search for a metallicity dependence similar to that for dwarfs by comparing our results for a sample of 22 giants earlier than K5 showing significant RV variations with a control sample of 58 relatively RV-stable stars.

Dome A, the summit of the Antarctic plateau, is expected to have even better atmospheric conditions for ground-based astronomy than Dome C.Instruments to evaluate and exploit Dome A's astronomical potentialmust operate within logistical constraints, which are currentlyvery stringent. Instrumentation now at Dome A exemplifies the techniques and solutions required by this environment. Future instrumentation and infrastructure will allow the qualities of the siteto be exploited much more fully.

We discuss the synergy of Gaia and the Large Synoptic Survey Telescope (LSST) in the context of Milky Way studies. LSST can be thought of as Gaia's deep complement because the two surveys will deliver trigonometric parallax, proper-motion, and photometric measurements with similar uncertainties at Gaia's faint end at r = 20, and LSST will extend these measurements to a limit about five magnitudes fainter. We also point out that users of Gaia data will have developed data analysis skills required to benefit from LSST data, and provide detailed information about how international participants can join LSST.

In recent years, a large amount of data has been collected with the aim to quantify the day- and nighttime astronomical observing conditions at Dome C. The available data show that the precipitable water vapor is below 0.75 mm in general, thus offering very good conditions for sub-mm observations. The extremely low temperatures of the atmosphere cause a very low background in the thermal infrared, which leads to significant savings in the time required to carry out large observing programmes. The absence of strong turbulence in the upper atmosphere results in a low scintillation and poses favorable conditions for photometric programmes. The free atmosphere seeing is of the order of $0\farcs 36$, but optical observations are impaired by the occurrence of a very strong turbulent boundary layer which reaches up to median altitudes of some 23 m in winter and up to some 400 m in summer. Detailed measurements of the vertical and temporal variation of the various parameters are now needed, in order to draw robust conclusions about short- and long-term stabilities and trends, and to constrain the specifications of future instruments that are eventually being deployed at Dome C.

Gaia will provide accurate parallaxes, spectrophotometry and spectroscopy for hundreds of thousands of emission-line stars across the whole HR diagram. In preparation for the Gaia mission, we are developing algorithms to recognize and classify emission-line stars. A large collection of ground-based spectroscopic observations has been collected and will be used for testing and training the algorithms.

Gaia will also provide information on several millions of early-type stars. Determining accurate parameters for these stars from Gaia data only will be difficult due to the AV – Teff degeneracy.

Our aim is to present new unified line profiles of sodium perturbed by H2 from the optical to the infrared spectral range. We compare the specific results obtained for the 3s-3p transition to laboratory spectra.

We discuss the role of Configuration Interaction (CI) and the influence of the number of configurations taken into account in the calculations of nickel and iron spectral opacities provided by the OPAC international collaboration, including statistical approaches (SCO, CASSANDRA, STA), detailed accounting (OPAS, LEDCOP, OP, HULLAC-v9) or hybrid method (SCO-RCG). Opacity calculations are presented for a temperature T of 27.3 eV and a density of 3.4 mg/cm3, conditions relevant for pulsating stellar envelopes.

ASTEP South is an Antarctic Search for Transiting ExoPlanets in the South pole field, from the Concordia station, Dome C, Antarctica. The instrument consists of a thermalized 10 cm refractor observing a fixed 3.88° × 3.88° field of view to perform photometry of several thousand stars at visible wavelengths (700–900 nm). The first winter campaign in 2008 led to the retrieval of nearly 1600 hours of data. We derive the fraction of photometric nights by measuring the number of detectable stars in the field. The method is sensitive to the presence of small cirrus clouds which are invisible to the naked eye. The fraction of night-time for which at least 50% of the stars are detected is 74% from June to September 2008. Most of the lost time (18.5% out of 26%) is due to periods of bad weather conditions lasting for a few days (“white outs”). Extended periods of clear weather exist. For example, between July 10 and August 10, 2008, the total fraction of time (day+night) for which photometric observations were possible was 60%. This confirms the very high quality of Dome C for nearly continuous photometric observations during the Antarctic winter.

The general formalism for Lyot and Roddier & Roddier coronagraphy is detailed. The influence of the masksize, chromatism and central obscuration are discussed. The necessity of entrance pupil apodization forcoronagraphy is introduced from the fundamental limitation that appears in the classical technique. Prolatespheroidal functions are presented as the natural apodizations for coronagraphy.

The huge amount of CCD photometric data collected by robotic telescopes (as for instance the ICE-T telescope to be installed at Dome-C) requires a fully automated approach to the reduction and analysis procedures. To this end, we are developing a pipeline, making use of IRAF, DAOPHOTII and tasks build up by us, which will enable to automatically extract differential magnitude time series. Both aperture and PSF photometry methods are used to build a proper sample of comparison stars, with the best method between the two being automatically selected. Finally, the search of rotational periods is performed. To test our package, we present results obtained using a 4-year dataset of a field in the Orion Nebula Cluster (ONC) containing about 350 stars (150 of which turned out to be periodic variables).

We give examples of where the Heun function exists as solutions ofwave equations encountered in general relativity. While the Diracequation written in the background of Nutku helicoid metric yieldsMathieu functions as its solutions in four spacetime dimensions,the trivial generalization to five dimensions results in thedouble confluent Heun function. We reduce this solution to theMathieu function with some transformations. We must applyAtiyah-Patodi-Singer spectral boundary conditions to this systemsince the metric has a singularity at the origin.

GAIA will likely be a real milestone for asteroid science. Itsunprecedented astrometric accuracy can be exploited to compute orbitsbetter than those obtained by using the whole set of availableastrometric observations carried out from ground during the last 100 years. GAIA will make it possible to measure asteroid masses throughthe measurement of the tiny displacements caused by asteroid mutualencounters. This will be a major breakthrough for physical studies ofminor planets. Moreover, sizes will be also directly measured for abig sample of more than 1000 objects. From masses and sizes, estimatesof the average densities will be also obtained. The spectrophotometriccapability of GAIA will be used for purposes of taxonomicclassification, with important implications for surface mineralogicalcharacterization. Finally, GAIA will be an ideal platform to detectnear-Earth asteroids having orbits interior to that of the Earth.

Gaia mission is underway conducting its 5 year lasting survey of the sky. At the moment the commissioning period has been completed and half a year worth of routine phase data has been collected. The status of the mission is outlined with short explanation of some commissioning phase findings and their impact on the mission. With a few examples of early mission data the potential of Gaia is demonstrated and we can conclude that the mission is capable meeting its high expectations.