A quantitative comparison between the Milne-Eddington (ME) inversion technique implemented by Skumanich & Lites and the SIR (Stokes Inversion based on Response Functions) proposed by Ruiz Cobo & del Toro Iniesta is presented. Numerical experiments are carried out to explore the capabilities and limitations of both diagnostic techniques. Such

Deep V and I CCD images of the loosely populated Galactic globular cluster Pal 1 and the surrounding field have been obtained with the Isaac Newton Telescope. A color-magnitude diagram (CMD) down to V(lim) 24 and a luminosity function down to V(lim) = 23.25 have been constructed. Adopting a reddening E(V - I) = 0.20 +/- 0.04 and comparing the CMD

We study the formation of the Li I lambda 6708 Angstroms resonance doublet in spectra of X-ray novae during the stage of outburst decay. We discuss the general conditions on accretion disc parameters which allow the detection of any spectral line absorption component in spectra of self-irradiated accretion discs. We obtain a simple analytical

The Faint Object Spectrograph on board the Hubble Space Telescope (HST) is used to obtain spectra in the wavelength range lambda lambda 1150-4800 of three planetary nebulae in the Small Magellanic Cloud and 10 planetary nebulae in the Large Magellanic Cloud. This sample extends the sample of 12 objects previously observed with HST and reported in

We present a systematic study of the radial brightness profiles in H alpha of a set of H ii regions in 6 late-type spiral galaxies, complete down to stated limiting luminosities. We have sufficient linear resolution in our observations to be able to fit models in which the effects of the radial fall off in density and in mean degree of ionization

Following the announcement of a new period of activity of the soft gamma-ray repeater SGR 1806-20 in 1996 November, we have performed follow-up observations of the IR counterpart, which has been proposed as a luminous blue variable or B[e] star. We have found that no variability larger than 0.1 mag in the K-band is present in the data. No variation