We describe the results of a search for transit-like events caused by giant planets occulting stars in the old, metal-rich open cluster NGC 6791 based on BVI-colour photometry from eight nights of observations with the 2.54 m Nordic Optical Telescope. To extract the light curves we have used both PSF photometry (DAOPHOT) and the difference imaging

The search for optical emission from radio hot spots has a long history but, up to now, only very few hot spots with optical synchrotron radiation have been detected. We embarked on a project to search for optical hot spot emission with VLT. We present the first results of near-infrared and optical imaging observations which detected synchrotron

We present a new general procedure for determining a given set of quantities. To this end, we define a certain statistic, which we call `modified χ2' (χ2M), because of its similarity to the standard χ2. The terms of this χ2M are made up of the fluctuations of an unbiased estimator of some statistical quantities and certain weights. Only the

We explain the linear polarization of the Ca ii infrared triplet observed close to the edge of the solar disk. In particular, we demonstrate that the physical origin of the enigmatic polarizations of the 866.2 and 854.2nm lines lies in the existence of atomic polarization in their metastable 2D3/2 , 5/2 lower levels, which produces differential

In this summary, a brief review is given of the main results presented during the workshop on astronomical site evaluation of San Pedro Mártir in Northern Baja California, Mexico, leading to to a summary of the most significant results related to San Pedro Mártir as a site for housing optical and infrared telescopes.

Echelle spectrophotometry of the planetary nebula NGC 5307 is presented. The data consist of Very Large Telescope Ultraviolet Visual Echelle Spectrograph observations in the 3100-10360 Å range. Electron temperatures and densities have been determined using different line intensity ratios. We determine the H, He, C, and O abundances based on