We present the results of a deep optical-near-infrared (optical-NIR) multi-epoch survey covering 2.5 deg2 of the Pleiades open star cluster to search for new very low-mass brown dwarf members. A significant (~5 yr) epoch difference exists between the optical (CFH12k I-, Z-band) and NIR (UKIRT WFCAM J-band) observations. We construct I, I - Z and Z

Many ground-based photometric surveys are now under way, and five of them have been successful at detecting transiting exoplanets. Nevertheless, detecting transiting planets has turned out to be much more challenging than initially anticipated. Transit surveys have learnt that an overwhelming number of false positives and confusion scenarios

We are all familiar with the fact that a linear flow of water in a tube can be obtained only for velocities below a certain critical limit and that, when the velocity exceeds this limit, laminar flow ceases and a complex, irregular, and fluctuating motion sets in. More generally than in this context of flow through a tube, it is known that motions

The MAGIC telescope took data of very high energy γ-ray emission from the blazar Markarian 421 (Mrk 421) between 2004 November and 2005 April. We present a combined analysis of data samples recorded under different observational conditions, down to γ-ray energies of 100 GeV. The flux was found to vary between 0.5 and 2 crab (integrated above 200

We report the discovery of a previously unseen X-ray point source detected in a 5ks observation starting on 2007-07-05.54 UT as part of our ongoing Chandra/HST M31 transient program. The source was detected on the edge of ACIS-S at coordinates RA(J2000) 00:40:59.2, Dec(J2000) +41:15:51.2, with centroid position errors of 2.4" and 3.0", respectively

A comparison between linear-stability analysis and observations of pulsation modes in five δ Scuti stars, belonging to the same cluster, is presented. The study is based on a work by Michel et al., in which such a comparison was performed for a representative set of model solutions obtained independently for each individual star considered. In this