Abstract: EST is a 4-meter class solar telescope to be installed in the Canary Islands with the first light expected in 2027. The EST design is optimised to observe the thermal, dynamic, and magnetic properties from the deep photosphere to the upper chromosphere simultaneously and thus enable to study the magnetic coupling between these layers. In this presentation we will describe the design baseline of EST, the current status of the EST project and the Czech participation in it.

Abstract: I will talk about the general relativistic magnetohydrodynamical simulations of accreting gas in a close vicinity of a black hole in different situations. The main accent of the talk will be put on recent results of the studies of low angular momentum accretion of matter onto Kerr hole, which may contain standing or oscillating shocks. The research has observable consequences on black holes on the whole mass scale, in particular, it could be related to the time-scale and shape of luminosity flares in Sgr A* or to the evolution of QPO frequency during outbursts of microquasars. I will also briefly mention the other interesting topic - the stability in 2D and 3D of stationary magnetized torus described by Komissarov (2006) and Montero et al (2007), which is a good starting model for further studies (e.g. the case of a disrupted torus by a stellar fly-by).

Abstract: The upper part of the Hertzsprung-Russell diagram is home to the most enigmatic types of massive stars, which serve as progenitors of various subclasses of core collapse supernovae.Obstacle in inderstanding the physics of such stars is the lack of observational data due to the rarity of these objects and, moreover, their short lifetime. Fortunately, these stars are frequently enshrouded behind their own dust, which renders them bright targets in the infrared. I aim to explore the extreme stellar content of other star-forming Local Group galaxies, by exploiting Group galaxies, by exploiting the wealth of archival data in the infrared and complementing with optical and near-infrared counterparts from the publicly available databases of 2MASS, SDSS, Hubble, Gaia. The upcoming time-series photometry from Pan-STARRS will further provide insight on the variable behaviour of these stars. Selection candidates will follow spectroscopic investigation essential for their proper classification and for the study of their circumstellar environment. Up to now my work on the post-RSG evolution in the M33 galaxy has successfully yielded a newly discovered Yellow Hypergiant candidate and several dusty yellow supergiants ideal for future investigation. By increasing the number of extreme, luminous objects in the Local Group galaxies, I aim towards a better understanding of the stellar evolution in diverse environments.

Abstract: A bright fireball was observed by the cameras of the Czech fireball network on September 9, 2016 at 23:06:59 UT. Moreover the video cameras at two separated stations recorded eight fainter meteors flying on parallel atmospheric trajectories within less than 2 seconds. All the meteors belong to the September epsilon Perseid meteor shower. The measured proximity of all meteors during a very low activity meteor shower suggests that a cluster of meteors was observed. The atmospheric trajectories of the observed meteors, masses and mutual distances of individual particles were determined using a double station observation. According to the distances and masses of the particles the most probable distance and time of fragmentation was determined. The observed group of meteors was interpreted as the result of the orbital fragmentation of a bigger meteoroid. The fragmentation happened no earlier than 2 or 3 days before the encounter with the Earth at a distance smaller than ~0.08 AU from the Earth.