Stationkeeping of quasiperiodic orbits near a periodic halo orbit of the Earth+Moon-Sun system is analyzed. The full solar system is considered as a perturbation of the restricted three body problem. In the full solar system the periodic orbits are lost but the system still has quasi periodic solutions relatively close to the previous halo orbits

SWIRE's wide-area multi-band coverage offers unprecedented opportunities for constructing large, unbiased AGN samples and for studying their cosmological evolution and physical properties. Here we present a collection of SWIRE results, namely on the infrared (IR) luminosity functions and on the tori characteristics of type-1 AGN. Type-1 AGN show

ELMER is an instrument for the GTC designed to observe between 365 and 1000 nm. The observing modes for the instrument at Day One shall be: Imaging, Long Slit and Mask-Multi-object Spectroscopy, Slit-less multi-object spectroscopy, Fast Photometry and Fast short-slit spectroscopy, over a FOV of 4.2 arcmin diameter. Spectral resolutions of 250, 1000

A full understanding of the properties of substellar objects is one of the major challenges facing astrophysics. Since their discovery in 1995, we have discovered hundreds of brown dwarfs and extrasolar planets. While these discoveries have enabled important comparisons with theory, observational progress has been much more rapid than the

Although the stellar and substellar populations have been studied in various young and old open clusters, additional studies in clusters in the the age range from 5 to 100 Myr is crucial (e.g. to give more constrains on initial mass function variation with improved statistics). Among the open cluster candidates from recent studies, two clusters are

The determination of atmospheric parameters is the first and most fundamental step in the analysis of a stellar spectrum. Current and forthcoming surveys involve samples of up to several million stars, and therefore fully automated approaches are required to handle not just data reduction but also the analysis, and in particular the determination