Brown dwarfs are objects unable to sustain hydrogen burning in their interiors. Deep surveys and large scale infrared surveys have identified a few hundred candidates free-floating in star clusters and in the solar neighborhood. Several brown dwarf companions to low-mass stars have also been detected. In the absence of a direct mass determination

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The K-band light profiles from two statistically complete, diameter-limited samples of disc galaxies have been simultaneously modelled with a seeing-convolved Sérsic r1/n bulge and a seeing-convolved exponential disc. This has enabled an accurate separation of the bulge and disc light, and hence an estimate of the central disc surface brightness μ0

We present V and R photometry of 16 Kuiper belt objects (KBOs) from the 3.6-m Telescopio Nazionale Galileo and the Complejo Astronómico El Leoncito 2.1-m telescope. We find a wide dispersion in the (V-R) colors of the objects, indicating nonuniform surface properties. If we assume near constant albedos, there does not appear to be a general trend

We present well-sampled uvby light curves, supplemented by a few β filter measurements, of the Algol binary VV UMa. The light curves are analysed using two different codes to derive the orbital and absolute stellar parameters of this binary. We find reasonably good fits to the light curves and determine the stellar effective temperatures Teff,1~

The equilibrium configuration of very small magnetic flux tubes in an intergranular environment automatically produces kilogauss magnetic field strengths. We argue that such a process takes place in the Sun and complements the convective collapse (CC), which is traditionally invoked to explain the formation of kilogauss magnetic concentrations in