Stopping of energetic sulfur and bromine ions in dense hydrogen plasma

The concepts of communicative space, media sphere and public sphere are sometimes used like synonyms one of the other. However, according to us, they are three different concepts: public sphere and media sphere are two distinct spaces symbolic systems which, both, are anchored in communicative spac

TraMoS project - III. Improved physical parameters, timing analysis and starspot modelling of the WASP-4b exoplanet system from 38 transit observations

International audienceWe report 12 new transit observations of the exoplanet WASP-4b from the Transit Monitoring in the South (TraMoS) project. These transits are combined with all previously published transit data for this planet to provide an improved radius measurement of Rp = 1.395 ± 0.022Rjup and improved transit ephemerides. In a new homogeneous analysis in search for transit timing variations (TTVs) we find no evidence of those with rms amplitudes larger than 20 s over a 4-yr time span. This lack of TTVs rules out the presence of additional planets in the system with masses larger than about 2.5, 2.0 and 1.0 M⊕ around the 1:2, 5:3 and 2:1 orbital resonances. Our search for the variation of other parameters, such as orbital inclination and transit depth, also yields negative results over the total time span of the transit observations. Finally, we perform a simple study of stellar spots configurations of the system and conclude that the star rotational period is about 34 d

TraMoS project - III. Improved physical parameters, timing analysis and starspot modelling of the WASP-4b exoplanet system from 38 transit observations

We report 12 new transit observations of the exoplanetWASP-4b from the Transit Monitoring in the South (TraMoS) project. These transits are combined with all previously published transit data for this planet to provide an improved radius measurement of Rp = 1.395 \ub1 0.022Rjup and improved transit ephemerides. In a new homogeneous analysis in search for transit timing variations (TTVs) we find no evidence of those with rms amplitudes larger than 20 s over a 4-yr time span. This lack of TTVs rules out the presence of additional planets in the system with masses larger than about 2.5, 2.0 and 1.0M around the 1:2, 5:3 and 2:1 orbital resonances. Our search for the variation of other parameters, such as orbital inclination and transit depth, also yields negative results over the total time span of the transit observations. Finally, we perform a simple study of stellar spots configurations of the system and conclude that the star rotational period is about 34 d. \ua9 2013 The Authors Published by Oxford University Press on behalf of the Royal Astronomical Society