High-precision HST photometry has revealed that the globular cluster (GC) NGC 2808 hosts a triple main sequence (MS) corresponding to three stellar populations with different helium abundances. We carried out photometry on ACS/WFC HST images of NGC 2808 with the main purpose of measuring the luminosity function (LF) of stars in the three different

Tadpole galaxies have a giant star-forming region at the end of an elongated intensity distribution. The origin of this asymmetric structure is not known, although suggestions range from ram pressure to mergers. We use SDSS data to determine the ages, masses, surface densities, and star formation rates of the heads and tails in 13 local tadpoles

El proceso de formación y evolución de las galaxias está determinado por dos conjuntos de mecanismos paralelos: (i) el ensamblado de la masa y sus interacciones con otros sistemas, que determinan su tipo morfológico y su evolución dinámica, que a su vez, induce formación estelar, y (ii) la formación, evolución y muerte estelar, que hace evolucionar

We perform simulations of feedback from supernovae and black holes with smoothed particle hydrodynamics. Such strong perturbations are inaccurately handled with standard time integration schemes, leading to poor energy conservation, a problem that is commonly overlooked. We show for the first time that, in the absence of radiative cooling

We are undertaking an ambitious proper motion survey of massive stars in the 30 Doradus region of the Large Magellanic Cloud using the unique capabilities of HST. We aim to derive the directions of motion of massive runaway stars, searching in particular for stars which have been ejected from the dense star cluster R136. These stars probe the

Spectroscopic surveys of stars in the Milky Way are growing rapidly in size and scope, with the ambitious goals of unravelling the Galaxy's formation and evolution, and finding out whether our galaxy fits the current paradigm of hierarchical galaxy formation driven by cold dark matter. These surveys follow target selection algorithms aimed at