Brown dwarfs are objects with masses, effective temperatures and luminosities intermediate between those of very low-mass stars and the most massive giant planets. In the last decade, numerous searches have revealed their ubiquitous presence in star forming regions and stellar clusters, orbiting stars and free-floating in the field. Hundreds of

Echo-tomgraphy is an indirect imaging technique which uses multiwavelength observations of LMXBs to constrain the fundamental parameters of these binaries. In particular, it uses time delays between X-ray and UV/optical light-curves as a function of orbital phase in order to map the reprocessing sites in a binary. Since previous works probe that

We have used multi-band high resolution HST WFPC2 and ACS observations combined with wide field ground-based observations to study the blue straggler star (BSS) population in the galactic globular cluster NGC 6388. As in several other clusters we have studied, the BSS distribution is found to be bimodal: highly peaked in the cluster center, rapidly

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Extensive spectroscopic studies of stars with and without planetary systems have concluded that planet host stars are more metal-rich than those without detectable planets. More subtle trends of different chemical elements begin to appear as the number of detected extrasolar planetary systems continues to grow. I review our current knowledge