Rotation is a key parameter in the evolution of massive stars, affecting their evolution, chemical yields, ionizing photon budget, and final fate. We determined the projected rotational velocity, υ e sin i, of ~330 O-type objects, i.e. ~210 spectroscopic single stars and ~110 primaries in binary systems, in the Tarantula nebula or 30 Doradus (30

Analysis of emission lines in gaseous nebulae yields direct measures of physical conditions and chemical abundances and is the cornerstone of nebular astrophysics. Although the physical problem is conceptually simple, its practical complexity can be overwhelming since the amount of data to be analyzed steadily increases; furthermore, results depend

The highly modulated optical light curve of HD 79826 (spectral types G5+M5) was discovered in the \chan guide-star light curves, indicating a period of about 0.5 days, a strong and migrating distortion wave, and a shallow eclipse. We subsequently obtained simultaneous \chan high resolution X-ray spectra and optical photometry, along with

Astronomers have studied the set of interstellar absorption features known as the diffuse interstellar bands (DIBs) for nearly a century, characterizing them into families and using them as probes of local interstellar medium (ISM) conditions even while trying to understand their origin. Though most DIB studies have focused on the optical features

With the help of CARMENCITA, the CARMENES Cool dwarf Information and daTa Archive, we investigate the multiplicity of M dwarfs in the solar neighbourhood observable from Calar Alto to prepare and characterize the final sample of CARMENES stars. Our multiplicity study covers a wide range in projected physical separations, from 0.5 to 55 000 au. The

Late stages of stellar evolution are characterized by copious mass-loss events whose signature is the formation of circumstellar envelopes (CSE). Planck multi-frequency measurements have provided relevant information on a sample of Galactic planetary nebulae (PNe) in the important and relatively unexplored observational band between 30 and 857 GHz