SLX 1737-282 is a persistent moderately bright X-ray source 1fdg2 from the Galactic center. X-ray observations with the Wide Field Cameras on BeppoSAX have for the first time revealed the true nature of SLX 1737-282: a 15 min long thermonuclear flash was detected exposing the source as a neutron star in a binary system. The flash was Eddington

The study of extragalactic extinction laws is of paramount importance as it plays a key role in galaxy evolution, as well as for the determination of the cosmological parameters, for example using SNe. We propose to utilize a new technique based on flux measurements of gravitationally lensed, multiply-imaged QSOs to estimate the extinction law of

We present the results of our monitoring of the halo black hole soft X-ray transient (SXT) XTE J1118+480 during its decline to quiescence. The system has decayed 0.5mag from 2000 December to its present near-quiescent level at R~=18.65 (2001 June). The ellipsoidal light curve is distorted by an additional modulation that we interpret as a superhump

The goal of this project is to analyze the integrated-light spectrum of a region in the LMC bar, for which HST images are already available yielding color-magnitude diagrams reaching the oldest main-sequence turnoff. Then, we can derive the star formation history in this field through evolutionary/population synthesis of the integrated light from

The photometric decay of sunspots is studied in some detail. Aspects related to leader vs. follower sunspot decay are presented and our current understanding of the physical mechanisms involved critically reviewed. The intrinsic instability of follower spots to form a stable sunspot cannot be understood in terms of the fluting stability as proposed

The probabilistic nature of the IMF in stellar systems implies that clusters of the same mass and age do not present the same unique values of their observed parameters. Instead they follow a distribution. We address the study of such distributions in terms of their confidence limits that can be obtained by evolutionary synthesis models. These