Only about 19 Galactic and 25 extragalactic bonafide luminous blue variables (LBVs) are known to date. This incomplete census prevents our understanding of this...

Context. Bulge globular clusters (BGCs) are exceptional tracers of the formation and chemodynamical evolution of this oldest Galactic component. However, until...

We surveyed a sample of compact Galactic planetary nebulae (PNe) with the Space Telescope Imaging Spectrograph on the Hubble Space Telescope (HST) to determine...

We present CH and CN index analysis and C and N abundance calculations based on the low-resolution blue spectra of red giant branch (RGB) stars in the Galactic...

We present deep echelle spectrophotometry of the brightest emission-line knots of the star-forming galaxies He 2-10, Mrk 1271, NGC 3125, NGC 5408, POX 4, SDSS...

We present C and O abundances in the Magellanic Clouds derived from deep spectra of H II regions. The data have been taken with the Ultraviolet-Visual Echelle...

We present an infrared (IR) characterization of the born-again planetary nebulae (PNe) A 30 and A 78 using IR images and spectra. We demonstrate that the carbon...

We present deep spectrophotometry of 18 H II regions in the nearby massive spiral galaxies M 101 and M 31. We have obtained direct determinations of electron...

We present an on-going project consisting of analysis of a sample of twenty-five metal-poor stars, most of them carbon-enriched and thus tagged carbon-enhanced...