We report optical and near-infrared (NIR) observations of the field containing the neutron star X-ray transient XTE J1739-285 (IAUC #7300, ATel #622). The recently reported Chandra localization (ATel #777) provides a significant improvement over the Swift XRT position reported in ATel #602, facilitating the identification of potential counterparts

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The MAGIC Cerenkov telescope has observed very high energy (VHE) γ-ray emission from the active galactic nucleus 1ES 1959+650 during 6 hr in 2004 September and October. The observations were carried out alternating with observations of the Crab Nebula, whose data were used as a reference source for optimizing γ -ray/hadron separation and for flux

By the time, in 1937, the Swiss astronomer Zwicky measured the velocity dispersion of the Coma cluster of galaxies, astronomers somehow got acquainted with the idea that the universe is filled by some kind of dark matter. After almost a century of investigations, we have learned two things about dark matter, (i) it has to be non-baryonic - that is

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Mercury's transit on the solar disk offers ideal conditions to determine the stray light level of instruments. We present here the results on the stray light level deduced from the observation of the Mercury transit on 2003 May 7th at the secondary focus of the THEMIS telescope with the broad-band and spectral channels of the IPM instrument. The