The ESO Laser Guide Star Facility is right now going through design phases, converging to an implementation foreseen in 2003. The LGSF has provisions for an upgrade to multiple LGS projection, foreseen in 2005/6 in the ESO Long Range Plan. We will tackle and discuss here the LGSF design choices, with an accent on the multiple LGS operation mode.

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Standard cosmology predicts that dwarfs were the first galaxies to be formed in the Universe and that many of them merge afterwards to form bigger galaxies such as the Milky Way. This process would have left behind traces such as tidal debris or tidal streams in the outer halo. We report here the detection of two new tidal debris of the northern

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We present R-band light curves of BL Lacertae from May 2000 to January 2001, obtained by 22 telescopes in 11 countries. More than 15000 UBVRI observations were performed in that period, which was the extension of the Whole Earth Blazar Telescope (WEBT) campaign originally planned for July-August 2000. The exceptional sampling reached allows one to

We have obtained HST-NICMOS observations of five of M31's most metal-rich globular clusters: G1, G170, G174, G177 & G280. For the two clusters farthest from the nucleus, G1 and G280, we statistically subtract the field population and estimate metallicities using K-(J-K) color-magnitude diagrams (CMDs). Based on the slopes of their infrared giant