We present intermediate dispersion (0.7-2.2 A/pixel) optical spectroscopic observations aimed at applying the 'lithium test' to a sample of 10 brown dwarf candidates located in the general field, two in young open clusters, and two in close binaries. We find evidence for strong Li depletion in all of them, and thus infer lower mass limits of 0.065

Using spectropolarimetric data of an Active Region (AR) filament we have carried out inversions in order to infer vector magnetic fields in the photosphere (Si I line) and in the chromosphere (He I line). Our filament lies above the polarity inversion line (PIL) situated close to disk center and presents strong Zeeman-like signatures in both

We have discovered small whirlpools in the Sun, with a size similar to terrestrial hurricanes (

The SAURON integral-field spectrograph was used to observe the central area of the barred spiral galaxy M100 (NGC 4321). M100 contains a nuclear ring of star formation, fueled by gas channeled inward by the galaxy's bar. We present maps of emission-line strengths, absorption-line strength indices, and the gas velocity dispersion across the field

A brief review is presented of infrared astronomical instrumentation which has been proposed or accepted for observations from space platforms. Some stress is placed on cryogenic design problems which have hitherto formed barriers to progress. Technical solutions to problems are outlined, and steps in implementing some of them are described.

The CoRoT satellite has provided high-precision photometric light curves for more than 163 000 stars and found several hundreds of transiting systems compatible with a planetary scenario. If ground-based velocimetric observations are the best way to identify the actual planets among many possible configurations of eclipsing binary systems, recent