The support costs of a system during the operational phase of its life-cycle represent a substantial part of the total life-cycle cost. Also, the support costs strongly depend on the decisions taken during the initial stages of the system design. However, traditionally many major systems have been developed attending only to the criteria deriving

INTEGRAL is an optical fiber unit for performing 2D spectroscopy of extended objects at the 4.2 m. William Herschel Telescope (WHT). It is mounted at the GHRIL Nasmyth focus together with newly built acquisition, guiding, and calibration units. It makes use of the specially designed fiber spectrograph WYFFOS. This system allows up to six bundles to

We describe multi-color observations with NICMOS and WFPC2 of 20 nuclei of nearby galactic bulges of types S0-Sbc. We find that the centers of 19 out of 20 bulges are found to be dusty, with average extinction A_V between 0.6 and 0.9 mag. Our second result is that the stellar populations of galactic bulges of type S0-Sb show a very tight B-I vs. I

From a new mosaic image in the H-α line of the complete disc of the spiral galaxy M100, a catalogue is composed listing 1948 individual HII regions. For each HII region, the catalogue gives its position relative to the centre of the galaxy, its deprojected distance to the centre, its radius, and its calibrated luminosity. An indication is included

IAUC 6967 available at Central Bureau for Astronomical Telegrams.

El estudio de la emisión IR en las galaxias Seyfert es fundamental para entender el origen de su extraordinaria actividad, así como para discernir la relación entre los distintos tipos de galaxias Seyfert. Dos importantes cuestiones no están aun resueltas. No está claro por ejemplo si la radiación IR de las galaxias Seyfert es toda de origen