The abundance gradient in M 33 is studied on the basis of IPCS and CCD data on emission lines in selected H II regions, using O II, O III, S II, and S III in...

Aims. The aim of this work is to shed some light on the problem of the formation of carbon stars of R-type from a detailed study of their chemical composition...

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...

We present deep spectra of ring nebulae associated with Wolf-Rayet (WR) and O-type stars: NGC 6888, G2.4+1.4, RCW 58, S 308, NGC 7635 and RCW 52. The data have...

New spectroscopic observations, including the optical and near-infrared ranges, have been obtained for a sample of HII regions located towards the Galactic...

We present new echelle spectrophotometry of the Galactic H II regions M8 and M17. The data have been taken with the VLT UVES echelle spectrograph in the 3100 to...

Context. Recent accurate abundance analyses of B-type main sequence stars in the solar vicinity has shown that abundances derived from these stellar objects are...

Aims: We re-examine the recombination/collisional emission line (RL/CEL) nebular abundance discrepancy problem in the light of recent high-quality abundance...

Context. Early B-type stars are invaluable indicators of elemental abundances of their birth environments. In contrast to the surrounding neutral interstellar...