We report on the latest inferences concerning solar differential rotation that have been drawn from the helioseismic data that are now available from the Solar Oscillations Investigation (SOI) using the Michelson Doppler Imager (MDI) on the Solar and Heliospheric Observatory (SOHO). That spacecraft is positioned in a halo orbit near the Sun-Earth

The paper describes an automatic inversion code to recover microstructured magnetic atmospheres (MISMAs) by fitting Stokes profiles. These solar model atmospheres incorporate small-scale fluctuations of the magnetic field vector, the velocity, the temperature, etc., which seems to be an intrinsic property of the magnetic photosphere. The model

{ We have studied high-resolution optical spectra of the peculiar B[e] star HD 45677 (FS CMa) observed during 3 nights in October 1995. The main results of our analysis can be summarized as follows: (1) The complex and variable profiles of Hβ indicate the presence of matter outflow. Three blue-shifted absorption components have been detected. (2)

We have obtained HST WFPC2 and NICMOS observations in the nuclear region of the closest powerful active galaxy known, NGC 5128 (Centaurus A). Narrow band imaging in the Paalpha line shows an elongated structure around the nucleus which we interpret as a disk of ionized gas, with a 15 pc radius. The disk does not appear to be perpendicular to the

We present intermediate- and low-resolution optical spectroscopy (650-915 nm) of seven faint, very red objects ( 20>I>=17.8 , I-Z>= 0.5) discovered in a CCD-based IZ survey covering an area of 1 deg2 in the central region of the Pleiades open cluster. The observed spectra show that these objects are very cool dwarfs having spectral types in the

We report on the discovery and analysis of a striking neutral sodium gas tail associated with comet C/1995 O1 Hale-Bopp. Sodium D line emission has been observed at heliocentric distance r