The magnetic field is the main driver of the activity in the solar upper atmosphere, but its measurement is notoriously difficult. In order to determine the magnetic field in the chromosphere, transition region, and corona, we need to measure and interpret the polarization signals that the scattering of anisotropic radiation and the Hanle and

Context. Comparing the properties of planets orbiting the same host star, and thus formed from the same accretion disc, helps in constraining theories of exoplanet formation and evolution. As a result, the scientific interest in multi-planetary systems is growing with the increasing number of detections of planetary companions. Aims: We report the

We present JWST/MIRI MRS spectroscopy of NGC 7319, the largest galaxy in the Stephan's Quintet, observed as part of the Early Release Observations (ERO). NGC 7319 hosts a type 2 active galactic nucleus (AGN) and a low-power radio jet (L 1.4 GHz = 3.3 × 10 22 W Hz −1) with two asymmetric radio hotspots at 430 pc (N2) and 1.5 kpc (S2) projected

Context. It is well known that cool star atmospheres depart from local thermodynamic equilibrium (LTE). Making an accurate abundance determination requires taking those effects into account, but the necessary non-LTE (hereafter NLTE) calculations are often lacking. Aims: Our goal is to provide detailed estimates of NLTE effects for FGK type stars

Context. Stellar rotation is of key importance in the formation process, the evolution, and the final fate of massive stars. Aims: We perform a reassessment of the empirical rotational properties of Galactic massive O-type stars using the results from a detailed analysis of ground-based multi-epoch optical spectra obtained in the framework of the

Context. Massive binaries hosting a black hole (OB+BH) represent a critical phase in the production of BH mergers in the context of binary evolution. In spite of this, such systems have so far largely avoided detection. Single-lined spectroscopic (SB1) O-type binaries are ideal objects to search for elusive BH companions. Moreover, SB1 binaries