We present spherically symmetric and plane-parallel photoionization models of NGC 346, an H II region in the Small Magellanic Cloud. The models are based on CLOUDY and on the observations of Peimbert, Peimbert, & Ruiz. We find that approximately 45% of the H ionization photons escape from the H II region, providing an important ionizing source for

A project to survey the entire visible sky for the presence of transits by extrasolar planets is presented. The experiment would consist of one or two fixed arrays of wide-angle cameras, that would take images of the entire sky more then 30 deg above horizon. A preliminary design consists of 15 cameras in each array, with optics based on SLR camera

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The relation between the X-ray, the coronal line and the infrared (IR) emissions in a sample of the brightest known Seyfert galaxies is analysed. A close relationship between the absorption-corrected soft X-ray emission and both the mid-IR and the coronal line emission is found for the Seyfert type 2 objects in the sample. The coronal line and the

New spectra of the Type Ic supernovae 1997B and 1997X at nebular phase are shown. Although one of them, SN 1997X, was studied with some detail around its maximum and its properties compared with other well-known SNe Ib/c, both of these events were later followed within its nebular phase. Our aim is to explore the behavior of these supernovae when

We observed EX Draconis in BV I colours for 40 nights, covering 3 outburst events, with the aim to study the disc evolution. Here, we present a preliminary eclipse-mapping study of some of the B band light curves obtained during the outburst in August 2000.