We have analyzed changes in the acoustic oscillation eigenfrequencies measured over the past 7 years by the GONG, MDI, and LOWL instruments. The observations span the period from 1994 to 2001 that corresponds to half a solar cycle, from minimum to maximum solar activity. These data were inverted to look for a signature of the activity cycle on the

The first theoretical investigation of the formation of the linearly polarized solar line spectrum of a complex atom, neutral titanium, is presented. The process of formation of line polarization is modeled by simply considering a plane-parallel layer of Ti I atoms illuminated from below by the photospheric radiation field, and accounting for the

We present the first results of an observational project, which addresses the period changing behaviour of a sample of high-amplitude delta Scuti stars. In this paper we discuss the double-mode nature of V567 Ophiuchi. It was observed on 15 nights in two consecutive years in order to resolve the long-standing ambiguity related to its secondary

The next generation of space- and ground-based spectropolarimeters demands new diagnostic tools capable of fast (ideally real-time) and reliable interpretation of the Stokes data. This paper presents a critical review of the various techniques that can be used for Solar magnetometry, from traditional approaches, such as the magnetograph formula, to

IAUC 7989 available at Central Bureau for Astronomical Telegrams.

From a comparison of the different parameters of warped galaxies in the radio, and especially in the visible, we find that: a) No large galaxy (large mass or radius) has been found to have high amplitude in the warp, and there is no correlation of size/mass with the degree of asymmetry of the warp. b) The disc density and the ratio of dark to