The Slow Merger of Massive Stars

We study the complete merger of two massive stars inside a common envelope and the subsequent evolution of the merger product, a rapidly rotating massive supergiant. Three qualitatively different types of mergers have been identified and investigated in detail, and the post-merger evolution has been followed to the immediate presupernova stage. The ``quiet merger'' case does not lead to significant changes in composition, and the star remains a red supergiant. In the case of a ``moderate merger'', the star may become a blue supergiant and end its evolution as a blue supergiant, depending on the core to total mass ratio (as may be appropriate for the progenitor of SN 1987A). In the case of the most effective ``explosive merger'', the merger product stays a red giant. In last two cases, the He abundance in the envelope is increased drastically, but significant s-processing is mainly expected in the ``explosive merger'' case.Comment: 4 pages, 1 figure, proc. ESO/MPA/MPE Workshop "From Twilight to Highlight: The Physics of Supernovae

ROLE PLAY AS A TECHNIQUE OF DEVELOPING LEARNERS' PROFESSIONALLY SIGNIFICANT COMPETENCES

The article addresses essential aspects of role play as a technique aimed at facilitating military students' professionally significant competences. The study undertaken here advocates the task-based language teaching as an integral part of the military students’ vocational training at the law faculty. Hence the goal of our study is to provide theoretical justification and methodological development of the concept of role play in foreign language teaching as a means of promoting second language learning and facilitating vocational training. We have analysed the impact of role play on the learner acquisition processes and forming of their professionally significant competences. We have identified stages and algorithms of role play, examined its components and characteristics in foreign language teaching. The conceptual framework of the study follows the model of professional competence approach. Research and experience data obtained in our experimental work make it possible to identify the significance of role play in second language learning designed for military students’ professional development in educational programs at law faculties.