We present observations of a new very low mass field binary, discovered during an infrared imaging survey of 250 DENIS L and very late-M dwarfs. DENIS-J055146.0-443412.2 is an M8.5 + L0 pair, with a physical separation of over 200 AU. This makes it the widest very low mass binary known in the field, by an order of magnitude. Such a system is

We report the first quiescent detection of KV UMa, the optical counterpart of XTEJ1118 + 480, in the near-infrared. The observed magnitudes and colours are consistent with a K7-M0V star, at the distance of 1.4 +/- 0.2 kpc. The light curve shows strong orbital modulation with possible contamination from a superhump detected in the quiescent optical

The double-mode pulsation of GSC 00144-03031 has been detected when searching for COROT targets. A very large dataset composed of 4722 photometric measurements was collected at six observatories in Europe and America. There is no hint of the excitation of additional modes (down to 0.6 mmag) and therefore GSC 00144-03031 seems to be a pure double

We discuss a 175 deg2 spectroscopic survey for blue horizontal branch (BHB) stars in the Galactic halo. We use the Two Micron All Sky Survey (2MASS) and the Sloan Digital Sky Survey (SDSS) to select BHB candidates, and we find that the 2MASS and SDSS color selection is 38% and 50% efficient, respectively, for BHB stars. Our samples include one

Most of what we know about the stellar population of nearby, resolved galaxies comes from the interpretation of their color-magnitude diagrams, by comparison with stellar evolutionary models. We review how well current stellar evolution models reproduce the properties of simple stellar populations. Emphasis is given to the regions of the color

We review some recent developments which make use of the concept of `superstatistics', an effective description for nonequilibrium systems with a varying intensive parameter such as the inverse temperature. We describe how the asymptotic decay of stationary probability densities can be determined using a variational principle, and present some new