Recent advances on the quest to determine the primordial or pregalactic helium abundance, Yp, are reviewed. There are seven problems affecting the He/H abundance determinations of H II regions that are briefly discussed: the underlying absorption lines in the observed spectra, the ionization, temperature, and density structures of each object, the

With the increasing availability of sensitive mid-IR area detectors on large telescopes there is a pressing need to increase the number and faintness of mid-infrared flux standards that are available. It is necessary to go as much as 4 orders of magnitude fainter in flux than the faintest ISO calibrators, although building on the foundations of the

We are carrying on several surveys in nearby galaxies aiming to find, catalogue and study old and young emission-line objects as H II regions, Planetary Nebulae, Symbiotic stars, SNRs to unprecedent levels. In particular, we are interested in extragalactic PNe and Symbiotic stars with subsequent spectroscopic study of each individual candidate. In

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Calibrated optical narrow-band imaging supplemented by near-infrared imaging of are Sh2-128 and Sh2-128N are presented. This region contains a developed H II region and a neighboring compact H II region associated with a pair of water maser sources. Midway between these the core of a CO cloud is located. Sh2-128 is an H II region at whose