We present broadband (gamma-ray, X-ray, near-infrared, optical, and radio) observations of the Swift gamma-ray burst (GRB) 090709A and its afterglow in an effort to ascertain the origin of this high-energy transient. Previous analyses suggested that GRB 090709A exhibited quasi-periodic oscillations with a period of 8.06 s, a trait unknown in long

High resolution spectroscopy demands detector operation in an extremely stable mechanical and thermal environment; any tiny perturbation may affect the location of the detected spectral lines, affecting the instrument global performance. The detector stability has been identified currently as one of the limiting factors to improve radial velocity

We present two conceptual optical designs for a new refractive corrector for the prime focus of the 4.2m William Herschel Telescope, optimised to allow wide-field multi-object spectroscopy. The proposed designs satisfy the demanding requirement that the PSF be smaller than 0.5 arcsec (80% encircled energy) over a two degree FOV and a wavelength

We investigate the role of stellar mass in shaping the intrinsic thickness of galaxy discs by determining the probability distribution of apparent axial ratios (b/a) for two different samples that probe the faint end of the galaxy luminosity function. We find that the b/a distribution has a characteristic `U-shape' and identify a limiting mass M* ~

The star formation rate (SFR) is a key parameter in the study of galaxy evolution. The accuracy of SFR measurements at z ~ 2 has been questioned following a disagreement between observations and theoretical models. The latter predict SFRs at this redshift that are typically a factor 4 or more lower than the measurements. We present star-formation

Context. The CoRoT mission is in its third year of observation and the data from the second long run in the galactic centre direction are being analysed. The solar-like oscillating stars that have been observed up to now have given some interesting results, specially concerning the amplitudes that are lower than predicted. We present here the