Aims.We present a detailed dynamical analysis of the rich galaxy cluster A2744, containing a powerful diffuse radio halo.Methods.Our analysis is based on redshift data for 102 galaxies, part of them recovered from unexplored spectra in the ESO archive. We combine galaxy velocity and position information to select the cluster members and determine

TrES-Her0-07621 is a recently discovered detached M Dwarf eclipsing binary system. We present some follow-up observations of this system including new minima times and a refined orbital period. We have also obtained better estimates of the stellar radii and inclination.

OO Ser is a deeply embedded young star which brightened by 5 mag between 1994 and 1995, and gradually faded afterwards. In many respects its eruption resembled the well-known FU Orionis-type (FUor) outbursts. Since very few such events have ever been documented at infrared wavelengths, we monitored OO Ser with the Infrared Space Observatory in the

We propose to perform H I observations of two starburst galaxies that show optical interaction features with surrounding objects and for which we have both broad-band and H-alpha imagery and optical spectroscopy. We will estimate the distribution of the atomic gas throughout the galaxies, looking for morphological features that reveal interaction

The long-duration γ-ray burst GRB 050713a was observed by the MAGIC Telescope 40 s after the burst onset and followed up for 37 minutes, until twilight. The observation, triggered by a Swift alert, covered energies above ~175 GeV. Using standard MAGIC analysis, no evidence of a γ-ray signal was found. As the redshift of the GRB was not measured

Due to an oversight at the editorial offices, the published version of our paper is missing the catalog table discussed in the text. We here give this table as Table 4, with the complete machine-readable table available in the electronic edition. In the text of the article, discussions of ``the catalog tables for each galaxy'' should refer to Table