We report on the development, calibration, and refinement of the SDSS-I Value Added Catalog (VAC) of stellar abundances, temperatures, and surface gravities. This catalog is based on observations of several hundred thousand stars obtained during the course of the original Sloan Digital Sky Survey, now known as SDSS-I. A spectroscopic pipeline has

We present new observational results on the RR Lyrae K-band Period-Luminosity relation (PLK). Data on the Galactic globular clusters NGC 3201 and NGC 4590 (M68), and on the Large Magellanic Cloud cluster Reticulum are shown. We compare the observed slopes of the PLK relations for these three clusters with those predicted by pulsational and

The Deep Impact mission was designed to have much of the mission-critial science done from Earth-based telescopes An unprecedent worldwide coordinated campaign was organized Many observatories around the world and in space observed the comet before during and after the impact to follow the effects of the event and its evolution The Roque de los

In order to better estimate the earth climatic variations at scales corresponding to decennia or centuries it appears more and more important to understand the internal origin of the solar magnetic cyclic activities together with the evolution of the internal solar rotation profile It is the only way to be able to predict how they will evolve in

From October 1999 to the present Chandra has taken nearly monthly snap-shot observations of M31. The first 3 years of this dataset in combination with deeper but less frequent XMM observations has allowed the detection of 45 X-ray transients within M31. By analogy to our Galaxy, many of these transients are likely black hole candidates. We have

We present a new calibration of the CaII triplet as metallicity indicator based in 4 globular and 11 open clusters which cover a range of metallicity - 2≤[Fe/H]≤+0.1 and age 13≤(Age/Gyr)≤0.25. We use it to derive the metallicity distribution in two fields situated at 5 and 8 degrees from the center of the LMC. We show that the mean [Fe/H] of the