This thesis focuses on the quantitative spectroscopic study of the O dwarf population in 30 Doradus (Large Magellanic Cloud, LMC), aiming at clarifying some long-standing open questions about the formation, evolution and physical properties of O stars during their main-sequence phase, where they spend most of their lifetime. This work has been

Dwarf elliptical galaxies (dEs) are the most common galaxy class in dense environments, outnumbering all other classes combined. Their low masses make them ideal test beds for studying different mechanisms that shape galaxies, since both external influences and internal feedback mechanisms are far more extreme in dwarfs than in massive galaxies

This thesis is focused in the study of the quiet Sun photosphere. In particular, in the high speed magnetized flows that can be observed in the solar surface. These events are distinguishable through the detection of highly distorted Stokes V profiles that trace the presence of magnetic plasma which is moving with very high velocities. We have

The study of primitive asteroids has gained much momentum in the last decade. The term "primitive" usually refers to objects with spectral characteristics similar to those of the carbonaceous chondrites, the most primitive meteorites. These meteorites contain pristine materials that have undergone very little processing since their formation, some

The topic of this thesis is the study of the morphology, kinematics and star formation of nearby galaxies, aiming to clarify a number of long-standing open questions about their formation, evolution and physical properties. First, I have addressed the star formation and its distribution across the Hubble sequence of galaxies. In particular, I have

La formación de galaxias y su evolución es a día de hoy una cuestión por resolver. En el escenario Lambda-CDM, las galaxias enanas son los componentes básicos de los cuales se forman las galaxias más grandes. Las enanas que observamos hoy en día podrían ser sistemas supervivientes que todavía no se han fusionado con galaxias más grandes y pueden