We report the results of CCD V and R photometry of the RRstars known in NGC4147. The periodicities of most variables are revised and new ephemerides are calculated. The Blazhko effect has been detected in V2 and V6. Three previously reported variables; V5, V9, and V15 are found to be non-variable. A new variable V18 was discovered with a period of

A catalogue of light curve solutions of contact binary stars has been compiled. It contains the results of 159 light curve solutions. Properties of contact binary stars were studied by using the catalogue data. As it is well known since Lucy's (1968ApJ...151.1123L, 1968ApJ...153..877L) and Mochnacki's (1981ApJ...245..650M) works, primary components

We present recent developments of the CAOS "system", an IDL-based Problem Solving Environment (PSE) whose original aim was to define and simulate as realistically as possible the behavior of a generic adaptive optics (AO) system, from the atmospheric propagation of light, to the sensing of the wave-front aberratoins and the correction through a

Not Available

Not Available

We present a study of beryllium (Be) abundances in a large sample of field solar-type dwarfs and sub-giants spanning a large range of effective temperatures. The Be abundances, computed using a very uniform set of stellar parameters and near-UV spectra obtained with 3 different instruments, are used to study the depletion of this light element. The