During the first few nights following its discovery, we observed the interstellar Ca II and Na I lines towards supernova 1993J at high spectral resolution (full width half maximum (FWHM) approximately 5-6 km/s) with the William Herschel Telescope at La Palma. We find a crowd of absorption components in the radial-velocity range -135 km/s less than

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Since the early 1970s, inversion techniques have become the most useful tool for inferring the magnetic, dynamic, and thermodynamic properties of the solar atmosphere. Inversions have been proposed in the literature with a sequential increase in model complexity: astrophysical inferences depend not only on measurements but also on the physics

We present an analysis of simultaneous observations of a sunspot in two different spectral ranges (630 nm and 1565 nm). The dataset was acquired with the POlarimetric LIttrow Spectrograph (POLIS) and the Tenerife Infrared Polarimeter (TIP) at the German Vacuum Tower Telescope (VTT) of Observatorio del Teide. Inversions of both sets of lines are

The GRAAL experimental set-up consists of a polarized and tagged photon beam that covers an energy range from a minimum of 600 MeV up to a maximum of 1500 MeV, of a liquid Hydrogen or Deuterium target and of the 4π Lagrange detector optimized for photon detection. It allows the study of pseudo-scalar and vector meson photoproduction on the nucleon

The characteristics of ionized and H I gas in the peculiar star/cluster complex in NGC 6946, obtained with the 6-m telescope (BTA) Special Astrophysical Observatory Russian Academy of Sciences (RAS), the Gemini North telescope, and the Westerbork Synthesis Radio Telescope, are presented. The complex is unusual as hosting a super star cluster, the