A programme of visible multi-colour monitoring of blazars was started in the Canary Islands in 1986. Infrared monitoring was added to the programme in 1988. The sample of objects to be observed is deliberately kept small to ensure that each one receives an acceptable level of light curve coverage. The programme was carried out using scheduled

We report on the discovery of a rapidly corotating stellar and gas component in the nucleus of the shell elliptical NGC 2865. The stellar component extends ~ 0.51 h_100^-1 kpc along the major axis, and shows depressed velocity dispersion and absorption-line profiles skewed in the opposite sense to the mean velocity. Associated with it is a young

The highly irregular nature of most photospheric magnetic fields is analyzed here, trying to emphasize the connection between photospheric fluctuations and those existing in the solar wind. It is discussed how the magnetic flux conservation in sunspots demands penumbrae pervaded by kilometer-wide irregularities. The diagnosis of this type of tiny

We have obtained high- and intermediate-resolution optical spectra of the black hole candidate Nova Scorpii 1994 in 1998 May/June, when the source was in complete (X-ray) quiescence. We measure the radial velocity curve of the secondary star and obtain a semi-amplitude of K_2=215.5 +/- 2.4 km s^-1, which is 6 per cent lower than the only previously

An objective of the GOLF experiment (Global Oscillations at Low Frequencies) on-board the SOHO (Solar and Heliospheric Observatory) space mission was to measure the line-of-sight component of the disk-averaged magnetic field of the Sun. In this paper, a theoretical study of this observable is presented. The newly developed techniques are tested

We continue our study of the young stellar object associated with IRAS 05327+3404. We have determined the spectral type of the central star to be K2. We show that the star is most likely seen directly, not via a reflection, and that the extinction is only A_V ~ 2.3 mag. The spectral energy distribution shows the presence of large amounts of