The long-standing difference in chemical abundances determined from optical recombination lines and collisionally excited lines raises questions about our understanding of atomic physics, as well as the assumptions made when determining physical conditions and chemical abundances in astrophysical nebulae. Here, we study the recombination

After almost 12 years gathering data with the 2.56-m Nordic Optical Telescope and the 1.2-m Mercator telescope, the IACOB project has broken the record of compiling high quality, multi-epoch, optical spectra for more than 1000 Northern Galactic O- and B-type stars. To celebrate this important milestone, in this contribution to the first virtual

Rotation is one of the important parameters affecting the evolution and final fate of massive stars. Still the origin of fast- rotating stars in the massive OB domain remains unclear. Although the high spin rates detected in about 20-30% of these stars could just be an imprint of the star formation process, alternative scenarios -supported by the

A large percentage of massive stars are born as part of binary or multiple systems. This statement, which has been defended by some authors during the last 3 decades -and has important consequences on the evolution, final fate and chemo-dynamical feedback of massive stars- has been recently confirmed by intensive spectroscopic, interferometric, and

The GTC Adaptive Optics (GTCAO) system will provide diffraction-limited capabilities in the near infrared to the GTC telescope. At first, it will use a Natural Guide Star (NGS) as a reference source, and later it will be upgraded to a Sodium Laser Guide Star (LGS), which will significantly increase the sky coverage. The GTCAO system is expected to

Context. Exoplanets orbiting very close to their parent star are strongly irradiated. This can lead the upper atmospheric layers to expand and evaporate into space. The metastable helium (He I) triplet at 1083.3 nm has recently been shown to be a powerful diagnostic to probe extended and escaping exoplanetary atmospheres. Aims: We perform high