We studied the fraction and properties of bars in a sample of about 3000 galaxies extracted from SDSS-DR5. This represents a volume limited sample with galaxies located between redshift 0.01 -20, and inclination i 60°. Interacting galaxies were excluded from the sample. The fraction of barred galaxies in our sample is 45%. We found that 32% of S0s

We analyze the timing of photons observed by the MAGIC telescope during a flare of the active galactic nucleus Mkn 501 for a possible correlation with energy, as suggested by some models of quantum gravity (QG), which predict a vacuum refractive index ≃1+E, n=1,2. Parametrizing the delay between γ-rays of different energies as Δt=±τE or Δt=±τE, we

This investigation aims to study the correlation of the solar background with atmosphere. We used high resolution observations of the NaDl spectral line. In fact the large span in formation heights of this spectral line allowed us to infer the signal from photosphere to chromosphere. We analyzed the data by applying the SIR code (Stokes Inversion

In 2005 a photometric observation campaign started on the open cluster χ Persei, involving 13 telescopes spread over the whole northern hemisphere. After two years we gathered almost 1200 hours of data. We present here preliminary results on the variability search, especially from the 60-cm telescope in Bialków (Poland), which show seven confirmed

We present PGos3, a database of evolutionary synthesis models and atmosphere libraries that compiles the Single Stellar Populations (SSP) results from different authors, covering more than 90% of the models used in the literature. PGos3 provides access to the models via WWW and in VOTable format accessible using TSAP protocol. Currently, a

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