The rapidly variable Seyfert 1 galaxy NGC 4151 will be the subject of an intensive monitoring campaign with IUE, Rosat, GRO, ASCA and ground-based telescopes in December 1993. We will report preliminary results of 9.3 days of continuous monitoring with IUE, at a sampling rate of once every ~ 80 min, an order of magnitude faster than that achieved

We have conducted a survey aimed at identifying a sample of z˜7-10 candidates accessible to detailed spectroscopic studies. The deep survey on A2667 covers a large field of view with HAWK-I and FORS2 at ESO/VLT between 0.8 and 2.5μm (typical depth m(AB)=27.5 at 3σ). 13 sources were identified based on the Lyman Break technique, namely 1 J-drop, 8 Y

We consider the compression of multispectral images using Hilbert scanning and adaptive arithmetic coding. The Hilbert scan is a general technique for continuous scanning of multidimensional data. Arithmetic coding has established itself as the superior method for lossless compression. The aim of this paper is to investigate the integration of the

We present here a part of the project aimed to study the SFH in different parts of the SMC. We observed 12 fields during a four year campaign (2001-2004) using the 100-inch Irénée du Pont telescope at Las Campanas Observatory, Chile, with positions ranging from ˜1° to ˜4° from the SMC center and located at different azimuths. In this poster we

We analysed high resolution spectra of Galactic O-type stars from the far-UV to the optical. We combined spectra from the Far Ultraviolet Spectroscopic Explorer (FUSE) in the range 905-1187Å, IUE or HST archive spectra (1150-3300Å), and optical blue and Hα spectra from the La Palma INT. The spectra were analysed with line-blanketed, hydrodynamic

We present time-resolved optical spectroscopy and photometry of four relatively bright (V˜14.0-15.5) long-period cataclysmic variables (CVs) discovered in the Hamburg Quasar Survey: HS 0139+0559, HS 0229+8016, HS 0506+7725, and HS 0642+5049. Their respective orbital periods, 243.69±0.49 min, 232.550±0.049 min, 212.7±0.2 min, and 225.90±0.23 min are