We analyze the old stellar population in the near infrared data around the Galactic plane of the 2MASS survey.

Aims: This work aims to provide a theoretical formulation of surface brightness fluctuations (SBF) in the framework of probabilistic population synthesis models that have no deterministic relations between the different stellar components of a population but only relations on average, and to distinguish between the different distributions involved

Full solar disk observations of radial velocity, obtained with the IRIS network of resonant scattering spectrometers, are used to analyze the acoustic p-mode spectrum around the acoustic cut-off frequency. Three different methods are used to determine it; two use the power spectrum, while the third uses the phase spectrum. The three values measured

Results of photometric surveys have brought to light the existence of a population of giant planets orbiting their host stars even closer than the hot Jupiters (HJ), with orbital periods below 3 days. The reason why radial velocity surveys were not able to detect these very-hot Jupiters (VHJ) is under discussion. A possible explanation is that

We have studied analytically the mean pull on shells of real (anisotropic and/or non-isolated) mass concentrations. Using a non-linear scheme, the radial component of the peculiar velocity is averaged over solid angle (V_0) and mass-averaged (V^*_0) for several different generic configurations. Nine Local Supercluster(LS)-like objects and six Great

We test the theoretical prediction that the straightest dust lanes in bars are found in strongly barred galaxies, or more specifically, that the degree of curvature of the dust lanes is inversely proportional to the strength of the bar. The test uses archival images of barred galaxies for which a reliable nonaxisymmetric torque parameter (Q b) and