We study the two-dimensional kinematics of the Hα-emitting gas in the nearby barred Scd galaxy NGC 6946, in order to determine the pattern speed of the primary m=2 perturbation mode. The pattern speed is a crucial parameter for constraining the internal dynamics, estimating the impact velocities of the gravitational perturbation at the resonance

Properties of bars and bulges in the Hubble sequence are discussed, based on an analysis of 216 disc galaxies of S0-Sm types (S0s from the Near-Infrared S0 Survey and spirals from the Ohio State University Bright Spiral Galaxy Survey). For this purpose we have collected, and completed when necessary, the various analyses we have previously made

We present results from a study on how the regolith surface affects the measured soft X-ray spectra from atmosphereless planetary surfaces as a function of viewing geometry. The analysis of the spectra obtained by orbiting spacecraft uses relative fluorescent elemental line intensities (e.g., Ca/Si, Fe/Si) as the first-order approach to determine

We implement the theory of resonant scattering in the context of cosmic microwave background (CMB) polarization anisotropies. We compute the changes in the E-mode polarization (EE) and temperature E-mode (TE) CMB power spectra introduced by the scattering on a resonant transition with a given optical depth τX and polarization coefficient E1. The

We present visible and near-infrared spectra of the nucleus of comet 28P/Neujmin 1, obtained in 2001, 2002, and 2003, while it had no detectable coma. The spectra show no strong features in this wavelength range, which prevented the identification of specific compounds on the surface of comet 28P. We found evidence for spectral variability, as our

The major objective of EURONEAR is high precision astrometry of Near Earth NEAs Asteroids (NEAs) and Potentially Hazarduous Asteroids (PHAs) observed in a coordinated network. During the last year, the activity was conducted toward the identification of the first dedicated 1m telescope to be automated and operated by an EURONEAR Consortium, as well