A considerable fraction of the massive stars of our galaxy is obscured by dust. Dust extinction is preventing us from using powerful criteria, developed at UV and optical wavelength ranges, to infer physical properties of hot stars. At wavelengths longwards of about 5 microns, emission from warm dust is typically dominating the spectra. It is

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The energy emission involved in a Gamma-Ray Burst evidently can be estimated only provided that we know the distance to the source. The same is true for the peak energy of the event in the source rest frame. Redshifts have been actually measured only for about 40 events. In order to check if it is possible to extend the Epeakrest E relation

The quiet-Sun photospheric plasma has a variety of magnetic field strengths going from zero to 1800 G. The empirical characterization of these field strengths requires a probability density function (PDF), i.e., a function P(B) describing the fraction of quiet Sun occupied by each field strength B. We show how to combine magnetic field strength

Exoplanetary transits produce a double-horned color signature that is distinct from both binaries and blends and can thus be used to separate exoplanets from false positives in transit searches. Color photometry with precision sufficient to detect this signal in transits of HD 209458 is available in the literature. Analysis of these observations

We describe the latest results and future prospects of the QUEST survey for RR Lyrae stars in the halo of the Milky Way. Because RR Lyrae variables are excellent standard candles, they are very useful tools for finding sub-structures in the halo that may be tidal tails from dwarf galaxies or globular clusters. Also, we show that observations of the