In this paper the approximate Lambda-Operator (ALO) developed by Olson, Auer and Buchler (OAB, 1986) is inspected from a more mathematical standpoint and compared to presently most commonly applied ALOs. For simple model calculations,it is shown that OAB's operator which contains no arbitrary parameter always works close to the optimum convergence

We stand on the threshold of a critical expansion of asteroseismology of Sun-like stars, the study of stellar interiors by observation and analysis of their global acoustic modes of oscillation. The Sun-like oscillations give a very rich spectrum allowing the internal structure and dynamics to be probed down into the stellar cores to very high

We have carried out a spectroscopic study of asteroid 65 Cybele in the 2 - 4 μm and 5 - 14 μm regions, using NASA's IRTF and Spitzer Space Telescope, respectively. We compare these spectra with those of Trojan asteroids and asteroid 24 Themis. Our target is the largest member of the Cybele population; these asteroids represent a transition group

Context. The evolved main-sequence Sun-like stars KIC 10273246 (F-type) and KIC 10920273 (G-type) were observed with the NASA Kepler satellite for approximately ten months with a duty cycle in excess of 90%. Such continuous and long observations are unprecedented for solar-type stars other than the Sun. Aims: We aimed mainly at extracting estimates

The preliminary results of a multisite photometric campaign on the Pleiades Delta Scuti variable V650 Tauri are reported. The star was observed photometrically for 14 days during 2008 November from three observatories distributed in Longitude around the Earth. As a result of the preliminary analysis we have detected in V650 Tauri at least nine

In order to characterized the vertical atmospheric structure at the Teide Observatory (Tenerife, Spain), we are using two different remote sensing technics: SODAR (SOund Detection And Ranging) and SCIDAR (SCIncitillation Detection And Ranging) at this astronomical site. We present in this work the preliminar results on the comparison of the