Spectra of late-type stars are usually analyzed with static model atmospheres in local thermodynamic equilibrium (LTE) and a homogeneous plane-parallel or spherically symmetric geometry. The energy balance requires particular attention, as two elements that are particularly difficult to model play an important role: line blanketing and convection

We have detected two globular clusters in the nuclear region of M31 with both Chandra and HST. These detections allow us to register the Chandra and HST images and therefore determine relative positions to ~0.1''. This improved positional accuracy shows that (contrary to our earlier reports) neither CXOU J004244.2+411608 nor CXOU J004244.2+411609

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