In this work we present new data that sets strong constraints on the solar oxygen abundance. Our approach, based on the analysis of spectropolarimetric observations, is almost model-independent and therefore extremely robust. The asymmetry of the Stokes V profile of the 6300 Å [O I] and Ni I blend is used as an indicator of the relative abundances

We present colour transformations for the conversion of the 2MASS photometric system to the Johnson-Cousins UBVRI system and further into the SDSS ugriz system. We have taken SDSS gri magnitudes of stars measured with the 2.5-m telescope from SDSS Data Release 5 (DR5), and BVRI and JHKs magnitudes from Stetson's catalogue (available at http://www2

For the large population of massive stars lying behind dust, among which are the youngests and potentially the most massive of our Galaxy, none of the commonly used wind diagnostics can be applied. As an alternative, a few observable infrared hydrogen lines are strong enough to hold wind diagnostics similarly to Hα. Using current state-of-the-art

We present the first photometry of individual stars within VV124 (UGC4879) and find that this is the most isolated dwarf galaxy in the periphery of the Local Group. This work is based on imaging and spectroscopic follow-up observations with the 6-m BTA telescope; we resolve VV124 into 1560 stars down to the limiting magnitude levels of V ~= 25.6

The atmospheric Cherenkov gamma-ray telescope MAGIC, designed for a low-energy threshold, has detected very-high-energy gamma rays from a giant flare of the distant Quasi-Stellar Radio Source (in short: radio quasar) 3C 279, at a distance of more than 5 billion light-years (a redshift of 0.536). No quasar has been observed previously in very-high

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