Context. The CARMENES spectrograph is surveying ˜300 M dwarf stars in search for exoplanets. Among the target stars, spectroscopic binary systems have been discovered, which can be used to measure fundamental properties of stars. Aims: Using spectroscopic observations, we determine the orbital and physical properties of nine new double-line

We present an abundance analysis of the star Cernis 52 in whose spectrum we recently reported the naphthalene cation in absorption at 6707.4 Å. This star is on a line of sight to the Perseus molecular complex. The analysis of high-resolution spectra using a χ2-minimization procedure and a grid of synthetic spectra provides the stellar parameters

We summarize the results of a chemical analysis of a sample of 23 galactic R stars (cool and warm spectral types) with accurate parallaxes measured by Hipparcos.

Spectroscopic observations obtained with the VLT of one planetary nebula (PN) in Sextans A and of five PNe in Sextans A and of several H ii regions in these two dwarf irregular galaxies are presented. The extended spectral coverage, from 320.0 to 1000.0 nm, and the large telescope aperture allowed us to detect a number of emission lines, covering

Context. Main-sequence massive stars embedded in an H ii region should have the same chemical abundances as the surrounding nebular gas+dust. The Cocoon nebula (IC 5146), a close-by Galactic H ii region ionized by a narrow line B0.5 V single star (BD+46 3474), is an ideal target to compare nebular and stellar abundances in detail in the same

New narrow-band images of NGC 4151, taken in excellent seeing conditions with the 4.2-m William Herschel Telescope are presented. These reveal a wealth of detail that can be used to test models for the anisotropy of the narrow-line region. From forbidden O III (4959, 5007)/H-alpha line ratio map, three important features are identified: (1) a jet