We lack a reliable scenario for the formation and evolution of stars and their planetary systems, involving key factors such as magnetic fields and turbulence. We present the case for a mission concept that will clarify these problems and give us a global view of the evolution of combined star and planetary systems. This will be achieved by

During the international OJ-94 campaign we have also monitored blazar 3C 66A. Since fall 1993 we have collected over 500 V-band observations. This constitutes more data than all the previous observations put together. During this monitoring the blazar was in outburst reaching V-magnitude 13.7 (JD 9414). This is the brightest it has ever been

We have studied the Lyα, Hβ, Hα, and Mg II λ2798 line profiles of the Seyfert 1 galaxy III Zw 2. The shapes of these broad emission lines show evidence of a multicomponent origin and also features that may be identified as the peaks due to a rotating disk. We have proposed a two-component broad-line region (BLR) model consisting of an inner

High-resolution spectra provide evidence of the Li-I 6707 line in 28 of the stars, and the significance of the results is discussed. The Li-I equivalent widths are presented after correcting for continuum veiling with actual measurements of the veiling itself. Surface spots are found to have a complex effect on the width of the photospheric lines

We present a quantitative derivation of the recent star formation history (SFH) in different regions in the main body of NGC 6822. It has been performed using a set of model CM diagrams computed under different assumptions for the recent (~400 Myr) SFH and in which the crowding effects have been simulated using the particular crowding information

Context: Over the past decade there have been a series of results supporting the hypothesis of the existence of a long thin bar in the Milky Way with a half-length of 4.5 kpc and a position angle of around 45°. This is apparently a very different structure from the triaxial bulge of the Galaxy, which is thicker and shorter and dominates the star