A significant fraction of massive stars in the Milky Way and other galaxies are located far from star clusters and star-forming regions. It is known that some of these stars are runaways, i.e. possess high space velocities (determined through the proper motion and/or radial velocity measurements), and therefore most likely were formed in embedded

This is the second article of a series devoted to European Extremely Large Telescope (E-ELT) site characterization. In this article we present the main properties of the parameters involved in high angular resolution observations from the data collected in the site testing campaign of the E-ELT during the design study (DS) phase. Observations were

Element abundance ratios hold important clues to understanding the evolution of stellar populations, through the varying timescales of different nucleosynthetic contributors. Newly measured and compiled [Mg/Fe] ratios in the MILES stellar library are used to confront models of star spectra. Such models have been used in recent years to provide

We are presently using the Chandra X-ray Observatory to conduct the first systematic X-ray survey of planetary nebulae (PNe) in the solar neighborhood. The Chandra Planetary Nebula Survey (ChanPlaNS) is a 570 ks Chandra Cycle 12 Large Program targeting 21 high-excitation PNe within ~1.5 kpc of Earth. When complete, this survey will provide a suite

The long-term time evolution of tidal dwarf satellite galaxieswith two different initial densities orbiting a host galaxy that resembles the Milky Way has been studied using a large set of Newtonian N-body simulations. From the simulations two maps of the orbital conditions that lead to quasi-equilibrium objects were constructed. It has been found

We present individual distances to three PNe: NGC 6537, NGC 6781 and NGC 7027, determined by the extinction-distance method. These objects are part of a larger sample (35) of PNe that we observed at ORM. In order to apply this method, and to obtain accurate distances, we determined the spectral type of 40 to 60 stars in the line of sight of each