We have surveyed Kepler’s supernova remnant in search of the companion star of the explosion. We have gone as deep as 2.6 L ⊙ in all stars within 20% of the...

Line scattering polarization can be strongly affected by Rayleigh scattering at neutral hydrogen and Thomson scattering at free electrons. Often a...

Observations of helium in exoplanet atmospheres may reveal the presence of large gaseous envelopes and indicate ongoing atmospheric escape. Orell-Miquel et al....

Confrontations of spectroscopic observations with local thermodynamic equilibrium (LTE) spectral syntheses in a three-dimensional (3D) hydrodynamical model of...

In this paper we address the problem of the non-LTE (NLTE) inversion of line profiles by means of a nonlinear least-squares minimization procedure combined with...

This paper presents a new diagnostic tool for the inference of the thermal, dynamic, and magnetic properties of the solar chromosphere. It consists of a non-LTE...

We test our knowledge of the atomic opacity in the solar UV spectrum. Using the atomic data compiled in the first paper in this series from modern, publicly...

Investigating the reliability of the assumption of instantaneous chemical equilibrium (ICE) for calculating the CO number density in the solar atmosphere is of...

First results from a high-resolution three-dimensional nonlinear numerical study of the kink oscillation are presented. We show in detail the development of a...