We present the results of the multisite differential CCD photometry for the two delta Scuti stars, BN and BV Cnc, in the open cluster Praesepe. The main objective was to identify the character of the pulsation modes in BN Cnc deriving their accurate periods, amplitudes and phases. These parameters are essential for the mode identification which

Recent observations of galaxy luminosity profiles and dark matter simulations find luminosity and mass distributions characterized by central cusps rather than finite core radii. We introduce and implement a set of cusped ellipsoidal lens models that include limits similar to the Jaffe, Hernquist, η and NFW models and apply them to the

Evolutionary synthesis models are a fundamental tool to interpret the properties of observed stellar systems. In order to achieve a meaningful comparison between models and real data, it is necessary to calibrate the models themselves, i.e. to evaluate the dispersion due to the discreteness of star formation as well as the possible model errors. In

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File table1.dat contains the log of the spectroscopic observations of the stars in the EXPORT sample taken with the Isaac Newton Telescope during the 1998 International Time Campaigns at the Canary Islands' Observatories. File table2.dat contains the log of the spectroscopic observations of the stars in the EXPORT sample taken with the William

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