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

Not Available

Since the beginning of this century we have attended a blooming of the gravity-mode research thanks to the unprecedented quality of the data available, either from space with SoHO, or from the ground-based networks as BiSON or GONG. From the first upper limit of the gravity-mode amplitudes fixed at 10 mm/s at 200 μHz given by Appourchaux et al.

In this Letter we present clear evidence that Mrk 573 is an obscured narrow-line Seyfert 1 (NLSy1) galaxy and not an archetypal Seyfert 2, as it has been classified until now. Only three galaxies have been proposed as members of this class, prior to this work. Here we report near-infrared spectroscopic data taken with LIRIS on the 4.2 m William

Since September 2007 we have been monitoring the optical counterpart (V, R and i-bands) of the black hole X-ray binary GX 339-4 with the Faulkes Telescope South situated at Siding Spring in Australia. The source has continued to decline from its 2006-7 outburst (ATel #968) until May 2008, in which a period of strong variability began. At its

Two extremely compact Hα-emitting sources have been discovered in our deep images of the Abell 539 and Abell 634 clusters of galaxies. Follow-up spectroscopy of these two unresolved sources have revealed that they are active starburst members of their respective clusters. The Hα luminosities and extreme Hα equivalent widths (of ≃ 430 Å and 1010 Å