Relativistic plasma jets are observed in many systems that host accreting black holes. According to theory, coiled magnetic fields close to the black hole accelerate and collimate the plasma, leading to a jet being launched1-3. Isolating emission from this acceleration and collimation zone is key to measuring its size and understanding jet

We present the first infrared ellipsoidal study of a low-mass X-ray binary system, and hence measure the mass of the neutron star. Photometry of Cen X-4 obtained during 1990-91 allows us to determine the quiescent light curve. By fitting this light curve with an ellipsoidal model we revise the ephemeris, obtain solutions in the mass ratio

We have compiled and studied photometric and spectroscopic data published in the literature of several star-forming regions and young open clusters (Orion, Taurus, IC 348, Sco-Cen complex, Chamaeleon I, TW Hydrae association, σ Orionis cluster, IC 2391, α Persei cluster, and the Pleiades). Our goal was to seek the definition of a simple empirical

The importance of the study of Planetary Nebulae (PNe) in our Galaxy and in external galaxies is outlined, with the aim of highlighting how the combined study of galactic and extragalactic PNe can bring a substantial contribution to our understanding of the late stages of stellar evolution and of related astrophysical topics. We then illustrate the

Aims: The spatial structure of the emission lines and continuum over the 50″ extent of the nearby, O-rich, PN NGC 7009 (Saturn Nebula) have been observed with the MUSE integral field spectrograph on the ESO Very Large Telescope. This study concentrates on maps of line emission and their interpretation in terms of physical conditions. Methods: MUSE

We describe the progress of a large optical and near-infrared imaging study of a complete sample of 57 spiral galaxies. We have obtained B, I, K' and Hα imaging to map stellar populations and massive star formation (SF) across the arm and interarm regions, in order to study the distribution of mass and SF in these different and distinct