The iron abundance of seven stars near the main-sequence (MS) turnoff and a giant in M67 are spectroscopically derived, and the results are discussed. The resulting mean iron abundance of the turnoff stars is (Fe/H) = 0.04 + or - 0.04. Taken together with previous determinations for younger clusters, this shows that there has been relatively little

The lithium (Li) abundance measured in the solar atmosphere is 140 times smaller than expected considering the proto-solar value. Furthermore, measurements of Li abundance made for many stars similar to the Sun reveal a large dispersion. These observations have defied the models of light element depletion for decades. We present a strong evidence

GJ 569Bab is the first brown dwarf binary for which the mass of each component has been derived by solving the astrometric and spectroscopic orbit of the pair, i.e., independently of any theoretical assumption. This allows us to test the predictions of the various evolutionary models available in the literature. Particularly interesting are the

We review several experiments in ionospheric modification performed at the HAARP facility. Many of these experiments have been done in bistatic configuration with the WAVES receiver on the NASA/WIND satellite, including study of scintillation-like variations in low frequency propagation through the earth's ionosphere and magnetosphere. The

We have analyzed long-slit spectroscopic data for a sample of tidally disturbed elliptical galaxies. Rotation curves and velocity dispersion profiles have been measured at a variety of position angles in these galaxies and have been used to analyze the dynamical response and internal kinematics of stellar systems involved in strong gravitational

We present 12 yr of monitoring of the gravitational lens Q0142-100 from the Teide Observatory. The data, taken from 1999 to 2010, comprise 105 observing nights with the IAC80 Telescope. The application of the δ2 method to the dataset leads to a value for the time delay between both components of the system of 72 ± 22 days (68% confidence level)