We report Hubble Space Telescope observations of six gravitational lenses with the Advanced Camera for Surveys. We measured the flux ratios between the lensed images in seven filters from 8140 Å to 2200 Å. In three of the systems, HE0512-3329, B1600+434, and H1413+117, we were able to construct UV extinction curves partially overlapping the 2175 Å

Brown dwarfs with thick water cloud atmospheres, ancient population III brown dwarfs, and nearby free-floating planetary mass objects are targets in our new discovery space. We have developed a candidate selection process that identifies near infrared sources without optical counterparts whose infrared/optical fluxes are not consistent with stars

A recent merger of two supermassive black holes (BH) or the presence of a second active BH in the galactic nucleus are two of the main scenarios proposed to explain the X-shaped morphology observed in X-shaped radio galaxies. We test these scenarios by studying the BH mass, radio and optical luminosity, starburst history and dynamic age of radio

We have analysed very high-quality HARPS and UVES spectra of 95 solar analogs, 24 hosting planets and 71 without detected planets, to search for any possible signature of terrestial planets in the chemical abundances of volatile and refractory elements with respect to the solar abundances. We demonstrate that stars with and without planets in this

Eclipsing binary (EB) systems showing double lines in their spectra are excellent sources of knowledge about structure and evolution of stars. The analysis of photometric and spectroscopic data in such double systems provides very accurate values for the absolute properties of both stars, as well as clues about their internal structure, their

We report the discovery of TrES-5, a massive hot Jupiter that transits the star GSC 03949-00967 every 1.48 days. From spectroscopy of the star we estimate a stellar effective temperature of T eff = 5171 ± 36 K, and from high-precision B, R, and I photometry of the transit we constrain the ratio of the semimajor axis a and the stellar radius R