We present accurate time delays for the quadruply imaged quasar HE 0435-1223. The delays were measured from 575 independent photometric points obtained in the R-band between January 2004 and March 2010. With seven years of data, we clearly show that quasar image A is affected by strong microlensing variations and that the time delays are best

We performed numerical simulations of mergers between gas-rich disc galaxies, which result in the formation of late-type galaxies. Stars formed during the merger end up in a thick disc that is partially supported by velocity dispersion and has high [α/Fe] ratios at all metallicities. Stars formed later end up in a thin, rotationally supported disc

We present the abundances of volatile and refractory elements in the atmospheres of 95 solar analogs, 24 planet hosts and 71 "single" stars, to investigate its possible connection with terrestial planets, using very high-quality HARPS and UVES spectra. The whole sample of stars with and without planets show almost the same mean abundance pattern

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Since the discovery of the first brown dwarfs (Tiede 1; Rebolo et al. 1995, Gliese 229B; Nakajima et al. 1995) the complement of identified brown dwarfs has grown to over 700. Yet our understanding of these cool objects is still somewhat lacking. Current models struggle to reproduce the observed variation in photometric and spectroscopic properties

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