Preliminary results of observations of 11 globular clusters made with the aid of a narrow long slit are presented. The photometric profiles were recorded directly in the operational store of a computer with the telescope stopped om iits motion about the polar axis. The photometric profile obtained were compared with King´s models and with the generalized sychrone model. The finite length and width of the slit were considered. The theoretical brightness distribution agrees well with observation in the central regions of the clusters at R < 3´- 5´. The radii of cores Rc and the effective radii Re were determined. Large-scale fluctuations of density, possible caused by bright stars, or by fluctuations of the abundant galactic background, were observed in clusters M12, M13 and NGC 6712.
The observed dynamical parameters of the Magellanic Clouds (MCs) clusters are derived by means of star counts. There are many rich globular, young disk clusters in the MCs with no counterparts in our galaxy. The old clusters were found statistically less extended with systematically smaller total masses than those of the galactic globulars. So it is worth emphasizing that clusters of all ages (from stellar evolution point of view) are detected in the MCs with very large total number of stars and structural parameters characterising the old halo galactic globulars.
The radial density profiles of these stellar systems were used for deriving information on their dynamical stage. Some of the clusters indicate mass segregation of post core collapse profiles, giving evidence for a two body relaxation mechanism. Nevertheless some very young clusters show well relaxed profiles with evolutionary ages too short for a two body relaxation mechanism, so that the
shape of their profiles is due to their initial relaxation.
A number of clusters were found with an unexpected distortion in the outer areas of their density profiles at systematically constant distances to their centres. It is probable that an halo is formed around these clusters giving evidence that the morphology of the MCs may favorite the occurence of such effects.
Úloha určování hmotnosti svazku klíčů byla v roce 2019 součástí okresního kola fyzikální olympiády kategorie G, tzv. Archimediády, v Českých Budějovicích. K řešení bylo možné dospět třemi různými postupy pomocí jednoduchých strojů. V textu příspěvku je naznačen možný postup řešení, analýza výsledků pilotáže a diskuze výsledků okresního kola., The assignment of determination of the mass of a bunch of keys was part of the district round of the Physics Olympiad (category G), the so-called Archimediáda, in České Budějovice in 2019. The solution could have been reached by three different procedures using simple methods. The text of this contribution presents a possible solution procedure, an analysis of the results received from piloting and a discussion of the results of the district round., and Vladimír Vochozka, Pavla Wegenkittlová.