Pravidelné semináře pořádáme jednou měsíčně (říjen–červen, zpravidla první pondělí v měsíci) od 13 hod v seminární místnosti pracoviště Ondřejov. (archiv seminářů)
01. 02. 2010
B[e] supergiants - a special evolutionary phase or the result from massive binary mergers?
Abstract: Stars with the B[e] phenomenon are a very heterogeneous group of emission line stars with strong near- and mid-infrared excess due to hot and warm circumstellar dust. Based on these characteristics, the group of B[e] stars was found to consist of stars in quite different evolutionary phases, ranging from pre-main sequence (Herbig stars) to post-main sequence phases (compact planetary nebulae and supergiants). Especially the B[e] supergiants, though studied in great detail, are far from being understood. About 15 B[e] supergiants are known to exist in the Magellanic Clouds, and I will first describe the difficulties in finding B[e] supergiants in our Galaxy. Then I will discuss the problematics in determining their proper place in the evolutionary path of massive stars. Finally, I will discuss the rather speculative but nevertheless interesting idea whether B[e] supergiants might result from massive binary mergers.
(seminář v angličtině)
Dále pořádáme menší semináře jednotlivých oddělení:
Semináře slunečního oddělení
Každé úterý v 12:45 (září–červen, s výjimkou úterků po celoústavním semináři) v zasedací místnosti slunečního oddělení pracoviště Ondřejov.
16/02/2010, 13:00Thin current sheets caused by plasma flow gradients in space and astrophysical plasmaAbstract: Often (Quasi-)Magnetohydrostatic is used for describing the slow change of magnetic structures in the solar atmosphere or planetary magnetospheres. The slow change of constraints or boundary conditions on the system or change of other external parameters often leads to the formation of current sheets. These current sheets often imply either a loss of equilibrium or the appearance of instabilities. Therefore such a picture of quasi-magnetohydrostatic changes fits to eruptive flares, coronal mass ejections and magnetospheric activities. We analyse the situation, allowing for flows, related to these kinds of magnetohydrostatic equilibria. Our analysis shows that shear flows along the field lines can also be responsible for the existence or generation of current sheets. In the talk some examples of such configurations will be shown.
Zářivě-(magneto)hydrodynamické semináře
Zpravidla 1x za 14 dní ve čtvrtek od 11 hod (říjen–červen) v zasedací místnosti slunečního oddělení pracoviště Ondřejov.
11.2.2010, 11:00Astronomický ústav, OndřejovEstimations of the total mass of solar prominences using multi-wavelength data
Semináře oddělení GPS
Zpravidla v knihovně pracoviště Praha–Spořilov v různé dny.
V nejbližší době nejsou plánovány žádné semináře.