We have monitored the photometric, spectroscopic and polarimetric variations of the classical T Tauri star (CTTS) AA Tau over a period of a month. The light curve consists of more than 260 measurements in each of the B and V-bands over a continuous time period of 30 days and more than 180 measurements in the R and I-bands. This provides

In a statistical analysis of Debrecen Photoheliographic Results sunspot area data we find that the logarithmic deviation (logD)' of the area decay rate D from the parabolic mean decay law (derived in the first paper in this series) follows a Gaussian probability distribution. As a consequence, the actual decay rate D and the time-averaged decay

ELMER is an optical instrument for the GTC designed to observe between 3650 and 10000 Armstrong. The observing modes for the instrument at Day One shall be: Imaging, Long Slit Spectroscopy, Mask-multi-object spectroscopy, Slit-less multi-object spectroscopy, Fast Photometry and Fast short-slit spectroscopy. It will be installed at the Nasmyth-B

Context. Blue compact dwarf (BCD) galaxies are low-luminosity, low-metal content dwarf systems undergoing violent bursts of star formation. They present a unique opportunity to probe galaxy formation and evolution and to investigate the process of star formation in a relatively simple scenario. Spectrophotometric studies of BCDs are essential to

Not Available

We discuss the method, and potential systematic effects therein, used for measuring the mass of stellar-mass black holes in X-ray binaries. We restrict our discussion to the method that relies on the validity of Kepler's laws; we refer to this method as the dynamical method. We briefly discuss the implications of the mass distribution of stellar