We are uncovering significant optical variability in low/hard state observations of several X-ray binaries on the fastest time-scales of just tens of milliseconds typically probed with modern rapid imaging cameras. The optical light curves are remarkable in that they display properties very characteristic of X-ray variations: 1) power spectra with

We report on RXTE observations of the ongoing outburst of the accreting millisecond X-ray pulsar SAX J1748.9-2021 (Altamirano et al. 2008, 674, 45A, see ATEL #2360 and #2407). Since the first detection of intermittent pulsations on January 27th, 2010, observations have been carried out on a daily basis. The source remained between 120 and 160 mCrab

Context. Helioseismology has enabled us to better understand the solar interior, while also allowing us to better constrain solar models. But now is a tremendous epoch for asteroseismology as space missions dedicated to studying stellar oscillations have been launched within the last years (MOST and CoRoT). CoRoT has already proved valuable results

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Context. The present number of Galactic open clusters that have high resolution abundance determinations, not only of [Fe/H], but also of other key elements, is largely insufficient to enable a clear modeling of the Galactic disk chemical evolution. Aims: To increase the number of Galactic open clusters with high quality measurements. Methods: We

The historic plates of the Carte du Ciel, an international cooperative project launched in 1887, offer valuable first-epoch material for the determination of absolute proper motions. We present the CdC-SF, an astrometric catalogue of positions and proper motions derived from the Carte du Ciel plates of the San Fernando zone, photographic material