We will report the results from an occultation of P126A by Pluto on the night of 2002 July 20 UT. The event was successfully observed with a 0.4-m telescope at Mamiña, Chile under photometric conditions. Additional data were collected at CTIO on a 0.6-m telescope with heavy interference from clouds. The CTIO observations preclude an occultation at

We report on Chandra ACIS-S observations of five type I X-ray bursters with low persistent emission: SAX J1324.5-6313, SAX J1752.3-3128, SAX J1752.3-3128I, SAX J1324.5-6313V, and SAX J1818.7+1424. We designate candidate persistent sources for four X-ray bursters. All candidates are detected at a persistent luminosity level of 1032-33 erg s-1

In an ongoing effort to study the formation and evolution of galactic bulges, we have investigated the position of 19 bulges of type S0-Sbc on the Fundamental Plane (FP). We find that bulges, in both B and K band, lie close to but slightly below the FP defined by ellipticals and S0s, i.e. are slightly brighter. There are hints that bulges of later

PKS 0537-441, a bright gamma -ray emitting blazar, was observed at radio, optical, UV and X-ray frequencies during various EGRET pointings, often quasi-simultaneously. In 1995 the object was found in an intense emission state at all wavelengths. BeppoSAX observations made in 1998, non-simultaneously with exposures at other frequencies, allow us to

We have discovered three certain (SAX J1324.5-6313, 2S 1711-339 and SAX J1828.5-1037) and two likely (SAX J1818.7+1424 and SAX J2224.9+5421) new thermonuclear X-ray burst sources with the BeppoSAX Wide Field Cameras, and observed a second burst ever from a sixth one (2S 0918-549). Four of them (excluding 2S 1711-339 and 2S 0918-549) are newly

Esta tesis forma parte de un proyecto a largo plazo cuyo objetivo es estudiar la evolución de los parámetros estructurales de las galaxias en función de su desplazamiento al rojo y en relación a la densidad local que las rodea. La meta principal de esta tesis ha sido desarrollar un software de análisis morfológico capaz de extraer información