According to the current theories of galaxy formation, these generally form as small entities that grow through fusion, collision and accretion, eventually becoming the majestic galaxies that we observe nowadays. As an example of such process we can mention our own galaxy, the Milky Way. Around it we can find tens of dwarf galaxies and even stellar “streams” formed by already dissolved systems. We have focused in the study of our two most prominent satellite galaxies, the Magellanic Clouds, a system in the process of falling towards our Galaxy, whilst also having a mutual interaction. Their

Planetary nebulae (PNe) are the ejecta of evolved low-intermediate mass stars present in all stellar systems. Perhaps the easiest thing to do when studying PNe in a galaxy is just counting how many of them appear with a given luminosity, the Planetary Nebula Luminosity Function (PNLF). Not surprisingly, just a few very bright, and many more fainter, PNe populate the PNLF. But, most surprisingly, the bright end bin of the PNLF has a remarkably constant cut-off value in all galaxies and stellar systems studied so far, both young and old, with just a mild, calibrateable dependence on

All disc-accreting astrophysical objects produce powerful disc winds. In compact binaries containing neutron stars or black holes, accretion often takes place during violent outbursts. The main disc wind signatures during these eruptions are blue-shifted X-ray absorption lines, which are preferentially seen in disc-dominated ‘soft states’. By contrast, optical wind-formed lines have recently been detected in ‘hard states’, when a hot corona dominates the luminosity. The relationship between these signatures is unknown, and no erupting system has as yet revealed wind-formed lines between the