In a recently published differential analysis (see ApJ, 724, 1536, Dec. 1 issue) , we have derived abundance corrections for iron lines, using synthetic spectra from solar magnetoconvection simulations that were performed via running the Copenhagen stagger-code on massively-parallel clusters. The series of 3D snapshots used for the spectral synthesis covers 2.5 solar hours in the statistically stationary regime of the convection.Crucially, we show that the effect of magnetic fields on solar abundancedeterminations can not be neglected. This is equally valid for all three different Fe

The CoRoT satellite discovers the first Jupiter-like exoplanet, which can be studied in detail when it passes in front of its central star. The CoRoT satellite, operated by the French space agency CNES, has discovered a Jupiter-sized planet orbiting a star similar to the Sun in the constellation Serpens Cauda at a distance of 1.500 light-years from the Earth. The parameters of this gas giant, which has features in common with the majority of exoplanets discovered so far, represents a valuable standard model when it comes to identifying new Jovian-type bodies with moderate temperatures

The quiet Sun (the 99%, or more, of the solar surface not covered by sunspots or active regions) is receiving increased attention in recent years; its role on the global magnetism and its complexity are being increasingly recognised. A picture of a rather stochastic quiet Sun magnetism is emerging . From these recent works, the quiet Sun magnetism is presented as a myriad of magnetic field vectors having an isotropical distribution with a cascade of scales down to the mean free path of the photon (1 marcsec, or 10km on the solar surface). But this chaotic representation also shows clear

Thanks to the NASA’s Spitzer Space Telescope, bucket loads of large carbon molecules, the so-called fullerenes (C 60), have been found around dying stars in the Milky Way and in a nearby galaxy. The fullerenes – the biggest molecules known in space – have been detected accompanied by large concentrations of hydrogen, contradicting the actual theories and the laboratory experiments, which show that fullerene formation is strongly inhibited by hydrogen. It turns out that fullerenes are much more common and abundant in the Universe than initially thought, because these molecules have been

Using images of the Advanced Camera for Surveys" of the Hubble SpaceTelescope we have analyzed the global physical parameters of thepopulations of HII regions in two galaxies: M51 and NGC 4449. M51 is a large spiral, in which we have measured and catalogued the Halpha luminosities, the radii, and the positions of more than 2000 of its HIIregions, while NGC 4449 is a dwarf irregular, in which we have catalogued over 200 HII regions. From these measurements we have obtained the mean electron densities, and have derived two simple but powerful relations. The electron density n_e of an HII

In this work we present a recent study of the bar fraction in the ComaCluster galaxies based on a sample of ~190 galaxies selected from theSloan Digital Sky  Survey Data Release 6 and observed with the Hubble Space Telescope (HST)  Advanced  Camera for Survey  (ACS).The unprecedented resolution of the HST-ACS  images allows us  to explore the presence of bars, detected by visual classification, throughout luminosity range of 9 mag (-23 < Mr < -14), permitting us to study th poor known region  of dwarf galaxies. We find that  bars are hosted bygalaxies in  a tight range of both  luminosities