High quality observations of the low-degree acoustic modes (p-modes) exist for almost two complete solar cycles using the solar spectrophotometer Mark-I, located at the Observatorio del Teide (Tenerife, Spain) and operating now as part of the Birmingham Solar Oscillations Network (BiSON). We have performed a Fourier analysis of 30 calibrated time

Las oscilaciones solares, y en concreto las frecuencias caracteristicas de estas, proporcionan una herramienta de diagnostico unica para investigar y entender la estructura y dinamica del sol. Estas frecuencias son modificadas de manera conocida por diferentes procesos permitiendo estudiar el origen fisico que los gobierna. En los ultimos años

Integral field optical spectroscopy using the INTEGRAL system has been used to characterize the kinematic and ionization properties of the warm gas within 2 kpc of the dust-enshrouded nucleus of Arp 220. Owing to the large internal extinction toward the nuclei, the brightest stellar and line-emitting regions observed at optical wavelengths do not

The aim of the SAURON collaboration, and the reason for building the instrument, is to study a representative sample of nearby ellipticals, lenticulars and bulges of early-type spirals, in order to measure their intrinsic shapes, velocity and metallicity distributions, and to gain insight into the relation between their stellar and gaseous.

Hubble Space Telescope (HST) and ground-based [O II] and [N II] images obtained in the period 1996-1999 reveal a complex, ionized optical nebula around the symbiotic binary CH Cyg extending out to 18" or 5000 AU from the central stars. The observed velocity range of the nebula, derived from long-slit echelle spectra, is 130 km s-1. In spite of its

We study the influence of gravitational microlensing on the spectral line profiles originating from a relativistic accretion disc. Using the Chen & Halpern model for the disc, we show the noticeable changes that microlensing can induce in the line shape when the Einstein radius associated with the microlens is of a size comparable to that of the