Due to the non-commutation of spatial averaging and temporal evolution, inhomogeneities and anisotropies (cosmic structures) influence the evolution of the averaged Universe via the cosmological backreaction mechanism. We study the backreaction effect as a function of averaging scale in a perturbative approach up to higher orders. We calculate the hierarchy of the critical scales, at which 10% effects show up from averaging at different orders, observable up to scales of 200 Mpc. The cosmic variance of the local Hubble rate is 10% (5%) for spherical regions of radius 40 (60) Mpc. We compare our results to the Hubble Space Telescope (HST) Key Project data.

We investigate the occurrence of water vapour signatures in a total of 10 red giants in the solar neighbourhood at mid-infrared wavelengths (12 μm). With the use of high resolution spectra from TEXES and synthesized spectra based on MARCS model atmospheres, we analyse the differences and discuss plausible causes. These include abundance adjustments, the addition of non-photospheric components (MOLspheres) and a different temperature profile.

Red supergiants (RSG) are a crucial phase in the evolution of massive stars. At solar metallicity, they represent the stage where substantial amounts of mass and angular momentum are lost. Here we investigate the role of RSGs at very low metallicity. We have computed evolutionary tracks at Z=0.0004 with and without rotation, using the latest version of the Geneva stellar evolution code. Here, we briefly discuss the evolution of RSGs, their lifetimes, mass ranges for forming RSGs, maximum luminosity of RSGs, and how these are affected by rotation.

We report on the facility we developed at the Observatoire de Meudon to test the Four Quadrant Phase Mask (4QPM) coronagraph in the Infrared (IR) and at low temperature. This facility has been developed in the context of the mid-IR instrument MIRI for the James Webb Space Telescope. Three 4QPM will take place inside MIRI and need to be qualified for space environment. The performance of the coronagraph is in agreement with our expectations from numerical simulations. The peak intensity of the diffraction pattern is reduced by a factor 380, a performance being limited by the chromatic effects and the size of the bench source.

Infrared spectroscopy is the best astronomical tool for studying the composition of cosmic dust. Thanks to the Herschel satellite, dust properties from the FIR to mm wavelength range will be sampled in different astrophysical environments. In the laboratory, the study of the temperature and structural dependence of FIR absorption of cosmic dust analogs including agglomeration is essential to interpret observational spectra. For crystalline materials, FIR single phonon bands are temperature dependent due to the anharmonicity of the vibrational potentials. This strong temperature dependence of the FIR bands’ positions can be used as a thermometer of the dust temperature. In amorphous material, the FIR absorption is dominated by disorder-induced single phonon processes and in the submillimeter and millimeter range by highly temperature-dependent low energy processes, e.g. tunneling transitions in two-level systems. The effect of these processes on the FIR absorptivity in amorphous silicates will be demonstrated.

The discovery that the short-lived radionucleide 60Fe was present in the oldest meteorites suggests that the formation of the Earth closely followed the death of a massive star. I discuss three astrophysical origins: winds from an AGB star, injection of supernova ejecta into circumstellar disks, and induced star formation on the boundaries of HII regions. I show that the first two fail to match the solar system 60Fe abundance in the vast majority of star forming systems. The cores and pillars on the edges of HII regions are spectacular but rare sites of star formation and larger clumps with masses 103-4 M๏ at tens of parsec from a supernova are a more likely birth environment for our Sun. I also examine γ-ray observations of 60Fe decay and show that the Galactic background could account for the low end of the range of meteoritic measurements if the massive star formation rate was at least a factor of 2 higher 4.6 Gyr ago.

An overview is given of the capabilities of the HIFI instrument on board of the HerschelSpace Observatory, its observing modes and its calibration. With the superb spectralresolution and wide frequency coverage of HIFI a plethora of astrophysical studies aredone.

First time-series observations with the 25-cm sIRAIT Antarcticpilot telescope from May 2007 are presented and show that the siteis well suited for time-series high-precision photometry. Ourtarget stars were one spotted 5.998-day rotating variable and oneshort-period δ-Scuti star. A total of 13 000 BVR CCDframes covered a time series of 243 consecutive hours.

The UFFO pathfinder mission will attempt to locate the optical afterglow of a GRB withinseconds of its detection and location by a wide field X-ray imager. It will be mounted onthe Lomonosov spacecraft for launch in 2013 and consists of a coded mask X-ray imager UBATto detect a GRB and estimate a direction vector which will be passed to the SMT opticalsystem which will rotate a moveable mirror to lock onto the GRB and direct the opticalafterglow to a camera with a  ~17′ wide aperture. We present the design geometry ofthe UBAT instrument only, with results of simulations for a range of GRB types to showprobable photon integration times to be expected to extract a significant FOV imagereconstruction and GRB location.

Atmospheric field experiments were made at the French-Italian station of Concordia at Dome C during several years. These experiments were limited to the summer season. In 2005 Concordia has become a permanent base, this allowed to carry out STABLEDC (STudy of the Atmospheric Boundary Layer Environmental at Dome C plateau station) that is an atmospheric field experiment of the duration of one year. The aim of STABLEDC was to study the processes occurring in the long-lived stable and the weak convective atmospheric boundary layers, observed during winter and summer, respectively, and to collect the relevant parameters for the atmospheric models. Both in situ and ground based remote sensing instruments have been used to monitor the meteorological parameters. The first part of the paper gives a brief illustration of the objectives of the field experiment, and a description of site and instrumentation. The second part shows the behaviour of some micrometeorological parameters: temperature, wind speed, sensible heat flux. The surface radiation balance components are also shown. Finally some experimental activities are proposed.

The gain of thermal infrared instruments in the 2–25 μm wavelength range from Antarctica is summarized by comparing three parameters: the ambient temperature; the atmospheric transparency, with perceptible water vapor content (PWV) in particular; and the image quality. For the 2 m class infrared telescope projects at Dome C the estimated mid infrared point source sensitivity can be compared to the sensitivities reached at 10 m class telescopes elsewhere. This comparison favors a thermal IR instrument at Dome C with focus on key science cases; two examples are: i) Survey type projects, such as mid infrared photometric imaging or spectro–polarization campaigns of YSO. Or ii) monitoring and rapid response observations on the Galactic Centre, the LMC, SN or GRB.

In this presentation, we first introduced the definition and classification of rotating sunspots. Using multi-wavelength data, we investigated the evolution of some rotating sunspots and the response of upper atmosphere relevant to the rotating sunspots. Moreover, the distribution of rotating sunspots in solar cycle 23 and the statistics of flares relevant to rotating sunspots are also presented.


Radio Astronomy in the U.S. went through two distinct phases, thepioneering phase before the Second World War, when Karl Jansky andGrote Reber were the only two radio astronomers in the world, and thepost-WWII era, when the subject blossomed throughout the world,especially in England and Australia, while U.S. radio astronomylanguished at a relatively low level, until its resurgence a decadelater. Here in Budapest we are celebrating the 70th anniversary ofJansky's discovery, and I shall start with a review of his work, andthe subsequent work of Grote Reber, who died, regrettably, in December2002. Two historical references will be cited frequently: Serendipitous Discoveries in Radio Astronomy (Kellermann & Sheets,eds. 1983, referred to as Paper 1) and the two historicalcollections edited by W.T. Sullivan, Classics in RadioAstronomy (1982, referred to as Paper 2) and The Early Yearsof Radio Astronomy (1984, Paper 3).

The observed brightness fluctuations and large-scale structures on thesurface of the Red Supergiant Betelgeuse make the star a prime targedfor future interferometric measurements. At the same time, they openthe possibility to resolve these structures in numerical radiationhydrodynamics simulations of the entire star. After some general remarksabout the possibility and difficulties of 3D simulations of stars ingeneral results of such calcuations of the outer convective envelope andthe atmosphere of a Red Supergiant and a star on the Asmyptotic GiantBranch are presented. These show that numerous short-lived small-scalesurface granules coexist with a few long-lived large-scale envelopeconvection cells. Pressure fluctuations deform the star and influencethe surface convection. The convective “granulation" pattern differsfrom the solar one. Convection and pulsations produce large-scalehigh-contrast brightness fluctuations that might explain the observedluminosity variations and surface “spots”. Shock waves and supersonicatmospheric velocities manifest themselves in broad line profiles.

We present preliminary results of the measurements of sky transparency conducted at Dome C during the winter 2008. Using MOLIERE modeling, we estimate a low precipitable water vapour content above Concordia station, which is very promising for future submillimetre wave observations on the Antarctic Plateau.

We explore the possibility that galaxy clusters or halos could besuited environments to host fermions like massive neutrinos in theirdegenerate state. Equilibrium density profiles for galaxy clustersand halos are calculated where the contribution of fermion particlesto an isotropic collisionless component is taken into account.Fermions are supposed to cluster in CDM protoclusters while theirphase space density is sufficient for not neglecting the Pauli'sexclusion principle.


Stars are not smooth. Their photosphere is covered by a granulation pattern associated with the heat transport by convection. The convection-related surface structures have different size, depth, and temporal variations with respect to the stellar type. The related activity (in addition to other phenomena such as magnetic spots, rotation, dust, etc.) potentially causes bias in stellar parameters determination, radial velocity, chemical abundances determinations, and exoplanet transit detections.

The role of long-baseline interferometric observations in this astrophysical context is crucial to characterize the stellar surface dynamics and correct the potential biases. In this Chapter, we present how the granulation pattern is expected for different kind of stellar types ranging from main sequence to extremely evolved stars of different masses and how interferometric techniques help to study their photospheric dynamics.