Context: The source 4U 2206+54 is one of the most enigmatic high-mass X-ray binaries. In spite of intensive searches, X-ray pulsations have not been detected in the time range 10-3-103 s. A cyclotron line at ~30 keV has been suggested by various authors but never detected with significance. The stellar wind of the optical companion is abnormally

We present the discovery of a 14-8+2 MJup companion located at 670 AU from UScoC-TIO 108, a 60+/-20 MJup brown dwarf of the very young Upper Scorpius association. Optical and near-infrared photometry and spectroscopy confirm that both the primary and secondary are very cool objects, with Teff of 2700 and 2100 K, respectively, and that they are bona

The MAGIC telescope observed the region around the distant blazar 3C 66A for 54.2 hr in 2007 August-December. The observations resulted in the discovery of a γ-ray source centered at celestial coordinates R.A. = 2h23m12s and decl. = 43°0farcm7 (MAGIC J0223+430), coinciding with the nearby radio galaxy 3C 66B. A possible association of the excess

We report the discovery of a giant, looplike stellar structure around the edge-on spiral galaxy NGC 4013. This arcing feature extends 6' (~26 kpc in projected distance) northeast from the center and 3' (sime12 kpc) from the disk plane; likely related features are also apparent on the southwest side of the disk, extending to 4' (~17 kpc). The

We describe optical spectroscopic observations of the icy dwarf planet Eris with the 6.5-m MMT telescope and the Red Channel Spectrograph. We report a correlation, that is at the edge of statistical significance, between blue shift and albedo at maximum absorption for five methane ice bands. We interpret the correlation as an increasing dilution of

We present narrowband images of the gravitational lens system Q 2237 + 0305 made with the Nordic Optical Telescope in eight different filters covering the wavelength interval 3510-8130 Å. Using point-spread function photometry fitting we have derived the difference in magnitude versus wavelength between the four images of Q 2237 + 0305. At λ = 4110