We present Doppler and modulation tomography of the X-ray nova XTEJ1118+480 with data obtained during quiescence using the 10-m Keck II telescope. The hotspot where the gas stream hits the accretion disc is seen in Hα, Hβ, HeI λ5876 and CaII λ8662, thus verifying the presence of continued mass transfer within the system. The disc is clearly seen in

The MAGIC Collaboration reports the detection of the blazar S5 0716+714 (z = 0.31 ± 0.08) in very high energy gamma rays. The observations were performed in 2007 November and in 2008 April, and were triggered by the Kungliga Vetenskapliga Akademi telescope due to the high optical state of the object. An overall significance of the signal accounts

First, a simple pre-whitening procedure was employed to find and subsequently remove periodic signals from the complex frequency structure of the radial velocity data. The dominant frequency in the power spectrum was found at 23 days, which corresponds to the rotation period of CoRoT-7. The 0.8535 day period of CoRoT-7b planetary candidate was

We present an implementation of stellar evolution and chemical feedback for smoothed particle hydrodynamics simulations. We consider the timed release of individual elements by both massive (Type II supernovae and stellar winds) and intermediate-mass stars (Type Ia supernovae and asymptotic giant branch stars). We illustrate the results of our

Aims: We aim to derive the chemical behavior of a significant sample of PNe and HII regions in the irregular galaxy NGC 6822. The selected objects are distributed in different zones of the galaxy. Our purpose is to obtain the chemical abundances of the present interstellar medium (ISM), represented by H ii regions, and the corresponding values at

Desde el espacio exterior llegan constantemente a la Tierra gran cantidad de particulas cargadas, la mayoria protones, aunque algunas veces tambien llegan nucleos atomicos que pueden ser tan masivos como el hierro. El espectro de estas particulas abarca un rango muy amplio de energia y sigue una ley de potencias. Este espectro plantea el problema