We study the disc emission component hidden in the single-peaked broad emission lines (BELs) of active galactic nuclei. We compare the observed broad lines from a sample of 90 Seyfert 1 spectra taken from the Sloan Digital Sky Survey with simulated line profiles. We consider a two-component broad line region model where an accretion disc and a

Star formation rates (SFRs) of galaxies are commonly calculated by converting the measured Hα luminosities (LHα) into current SFRs. This conversion is based on a constant initial mass function (IMF) independent of the total SFR. As was recently recognized, the maximum stellar mass in a star cluster is limited by the embedded total cluster mass and

Results of coordinated observations of the flare star EV Lac in September 1992 are presented. Among 25 flares detected during 28 hours on patrol in Crimea four had large enough amplitudes to permit the quantitative analysis of their radiation by colour-colour diagrams. Calculation of V-I colour index for different radiation sources enable us to

All the projects of the Extremely Large Telescopes (ELTs) are based on segmented primary mirrors. This idea, solving the problem of producing single mirrors having diameter larger than 8m, introduces the needs for an accurate co-phasing of the various segments. The paper presents some laboratory measurements aimed to investigate the use of the

Context. Precise stellar parameters (effective temperature, surface gravity, metallicity, stellar mass, and radius) are crucial for several reasons, amongst which are the precise characterization of orbiting exoplanets and the correct determination of galactic chemical evolution. The atmospheric parameters are extremely important because all the

We have obtained (in BVRI filters) the structural parameters of four disk galaxies, spanning a range of different morphological types. We believe the parameters are reliable because an extensive part of the galaxies' disks are free from contamination by other components, and a detailed photometric method has been used to derive these quantities