We present the results from an optical monitoring campaign aimed at studying the afterglow properties of the short GRB 100816A. We implemented a new way of processing the Swift-BAT data, and based on it we reclassified this burst as short, discarding the initial classification as long. Observations were carried out mainly with the GTC Telescope

Long gamma-ray bursts (GRBs) pinpoint star-forming galaxies as they are linked to the deaths of massive stars. In most cases, these galaxies have been found to be blue, sub-luminous and of low-metallicity. However, our recent survey have demonstrated that a sizeable fraction of GRBs reside in massive, dusty and star-forming extremely red objects

We have discovered a ˜420-d modulation, with associated X-ray dips, in Rossi X-Ray Timing Explorer-All Sky Monitor/Monitor of All-Sky X-ray Image/Swift-Burst Alert Telescope archival light curves of the short-period (3.2 h) black hole X-ray transient, Swift J1753.5-0127. This modulation only appeared at the end of a gradual re-brightening

We report the discovery of 76 new T dwarfs from the UKIRT Infrared Deep Sky Survey (UKIDSS) Large Area Survey (LAS). Near-infrared broad- and narrow-band photometry and spectroscopy are presented for the new objects, along with Wide-field Infrared Survey Explorer (WISE) and warm-Spitzer photometry. Proper motions for 128 UKIDSS T dwarfs are

Context. It has recently been discovered that the Galactic bulge is X-shaped, with the two southern arms of the X both crossing the lines of sight at l = 0 and | b| > 4, hence producing a double red clump in the bulge color magnitude diagram. Dynamical models predict the formation of X-shaped bulges as extreme cases of boxy-peanut bulges. However

Uno de los parámetros mas relevantes en la descripción del Universo es la densidad bariónica media. Esta ha sido estimada a través de las abundancias de los elementos primordiales y confirmada en estudios recientes del espectro de potencias del Fondo Cósmico de Microondas (FCM). Sin embargo, las observaciones de la materia bariónica en el universo