We present new photometric data for seven high-amplitude delta Scuti stars. The observations were acquired between 1996 and 2002, mostly in the Johnson photometric system. For one star (GW UMa), our observations are the first since the discovery of its pulsational nature from the Hipparcos data. The primary goal of this project was to update our

In this work we present a multiwavelength study of narrow-line Seyfert 1 galaxies (NLS1s) discovered in the Second Byurakan Survey (SBS). The sample consists of 26 objects, which have MB>=-23.0, or -19.9>MB>-23.0, 0.0243 1). The traditional linear correlation LX and Lop, which seems to hold for active galactic nuclei in general, is found for SBS

High spatial resolution visible and NIR observations of the bar of NGC 5850, a prototype of double barred spirals, together with visible intermediate and high dispersion spectra along the primary bar, are being used, with the aid of simple stellar population synthesis models, to investigate the mean age and metallicity of the different stellar

We present optical and near IR follow up observations of the dark GRB 001109, 1-300 days after the event. No transient emission has been found for these wavelengths within this GRB's (Gamma Ray Burst) BeppoSAX 1' radius error box. Strong limits are set with K' > 20. A highly reddened galaxy, with variable radio emission, was found at z = 0.398. It

The Mn I 543.25 nm spectral line has unusually broad line profile due to its hyperfine structure. Here we present the results of LTE calculation of the synthetical profile of the Mn I 543.25 nm line in the solar spectrum. We used the Oxford total absorption oscillator strength measurements as the first approximation for hyperfine structure. The

We present new results on the Hubble diagram of distant type Ia supernovae (SNeIa) segregated according to the type of host galaxy. This makes it possible to check earlier evidence for a cosmological constant by explicitly comparing SNe residing in galaxies likely to contain negligible dust with the larger sample. The cosmological parameters