A mayor problem that arises in the computation of stellar atmosphere models is the self consistent determination of the temperature distribution via the constraint of energy conservation. The energy balance includes the gains due to the absorption of radiation: int χ(ν) J(ν) dν, and the losses due to emission: int χ(ν) S(ν) dν . It is well known

Los asteroides son objetos que no poseen atmósfera cuyo tamaño es menor que el de los planetas y que orbitan alrededor del Sol. La principal población de estos objetos se encuentra entre las órbitas de Marte y Júpiter, en el denominado "cinturón principal" (main belt, MB). Dentro de los asteroides son de especial interés los asteroides cercanos a

The discovery of V Indi Ba and Bb, a nearby binary brown dwarf system with a main-sequence companion, allows a concerted campaign to characterise the physical parameters of two T dwarfs providing benchmarks against which atmospheric and evolutionary models can be tested. Some recent observations suggest the models at low mass and intermediate age

Velocity oscillations "measured" simultaneously at the photosphere and the chromosphere—from time series of spectropolarimetric data in the 10830 Å region—of different solar magnetic features allow us to study the properties of wave propagation as a function of the magnetic flux of the structure (i.e., two different-sized sunspots, a tiny pore, and

Context: A planetary nebula (PN) candidate was discovered during FORS imaging of the Local Group dwarf galaxy Phoenix. Aims: We use this PN to complement abundances from red-giant stars. Methods: FORS spectroscopy was used to confirm the PN classification. Empirical methods and photoionization modeling were used to derive elemental abundances from

The Universal Transit Modeller (UTM) is a light-curve simulator for all kinds of transiting or eclipsing configurations between arbitrary numbers of several types of objects, which may be stars, planets, planetary moons, and planetary rings. Applications of UTM to date have been mainly in the generation of light-curves for the testing of detection