Pavol Zigo

The Bologna-Modra forward-scatter radar experiment: reflection properties of meteor trains

Abstract Observational results on the reflection properties of meteor trains obtained by forward-scatter bistatic radar over the baseline Bologna Modra (about 700 km), as well as some characteristics of the Lyrid shower meteors in 1993, are presented here. The observations following the shower radiant motion showclearly that the orientation of the baseline of the forward-scatter system is the dominating factor affecting the flux of the recorded meteors. Even the long-enduring meteor trains which were proved to be independent in a backscatter system of the specular reflection conditions, are observed herewith to be strongly dependent on the baseline orientation with a maximum rate corresponding to the radiants having the baseline as azimuth.

The analysis of polar compounds in cigarette ashes by GC–MS/MS

The newly developed gas chromatography–tandem mass spectrometry method allows the analysis of non-volatile, polar substances in cigarette ash. Only a few mg of ash, derivatized by two-step silanization with hexamethyldisilazane and N,O-bis(trimethylsilyl)trifluoroacetamide, are necessary for the analysis. Samples are directly analyzed after derivatization, without the need of extraction as a next purification step. Differences in chromatographic profiles reflect the composition uniqueness of each matrix and can be used for product authentication by chromatographic fingerprint method. The method was used to differentiate between cigarette ash samples of three cigarette brands (Marlboro, Davidoff, and West) and can be useful for forensic purposes.Graphical abstract

Observation of collision of comet Shoemaker-Levy 9 with Jupiter at the Astronomical and Geophysical Observatory in Modra

A report about observations of collision of the comet Shoemaker-Levy 9 with Jupiter is presented. The observations were made both in optical and radio wavelengths. Some consequences of impacts of individual fragments of the comet were detected visually in the 20-cm refractor. 21 days prolonged series of records on a video tape was taken in the focus of the 60-cm reflector, too. 13 serious events from July 16, 1994 to July 23, 1994 on 42.7 MHz radio wavelengths were registered. Its coherence with the pair Shoemaker-Levy 9 and Jupiter in the interaction is the subject of further investigation. More comprehensive results will be published after collecting information about similar observations on radio waves all over the world.