High resolution (better than 1") magnetograms obtained at the Sacramento Peak Vacuum Tower Telescope were used to study the decay of a small active region. The reduction process allows one to match intensity and magnetic pictures exactly. Some of the main results are; (i) The granulation massages a magnetic pore, probably inducing its fragmentation. The supergranules get rid of the decayed pieces transporting them away from the pere. (ii) Magnetic flux is removed from the photosphere through its submergence.
Na jedinečnou vzdělávací akci, která se konala od 3. do 10. července 2017 v prostorách Matematicko-fyzikální fakulty v Troji, přijely čtyři desítky nejlepších řešitelů astronomických olympiád z České republiky, Estonska, Maďarska, Polska a Slovenska. Na programu byly vedle výpočetníích seminářů také zvané přednášky přístupné široké veřejnosti, večerní pozorování, výjezd do planetária v Hradci Králové, exkurze na odřejovskou observatoř a komentovaná procházka po pražských astronomických památkách. Účastnící si rovzněž vyzkoušeli atmosféru mezinárodní olympiády při simulované souteži. and Jakub Vošmera, Jan Kožuško, Václav Pavlík.
High resolution and high signal to noise ratio CCD observations
of 59 Cyg show periodic variations in the radial velocities of
the components of Hα-line, i.e. of the absorption component,
and of the intensity ratio of the blue and red emission components. The period 29.14 d suggest duplicity of this star.
The very young LMC clusters SL666, NGC2098 and NGC2100 were found to exhibit a variation of spectral types with distance from the cluster centre. From spectral dassification of their bright members it is found that the early type stars are accumulated in the inner region of the cluster whereas the late type ones are found in the outer areas. Star counts on photographic plates with different exposure times have shown that the bright stars are segregated in the central regions of the clusters. Both observational results from spectral classlfication and star counts give evidence that the most massive early type stars are located in the inner parts of the clusters. This allow us to suggest that the observed mass segregation is not due
to the relaxation mechanism of the clusters.
Simultaneous observations of the H-alpha and Ca II K floccular lines show that during the first three days of the newly formed flocculi the temperature grows gradually, while the density is practically constant. During the following days an increase in density is observed, The phase of increasing density does not occur in the case of faint flocculi. The K-line analysis of the six newly - formed sunspots indicates that the average cooling upward velocity equals 15 ms”' . An increase in sunspot induction was observed at the time of the flares (46 spots, Fig. 5).
The time profiles of the solar microwave emission exhibit various phenomona reflecting the evolution of magnetic flux tubes before and during the onset of flare events. Different scenarios are posslble to describe the processes of energy release in a flux tube and the interaction of a number of tubes during the preflare stage and the early flare development, Multi-peak structures at quite
different time scales displayed by flux records at mm-, cm-, and dm-waves are examined; they rise the question how to distinguish between repeated energy release at one site and the propagation of the flare disturbances over an extended source area, A discussion of observed time scales and released energy in the frame of some scenarios is carried out.
H3+, nejjednodušší mnohoatomový iont, je klíčovým prekurzorem řady chemických reakcí vedoucích ke vzniku komplexních sloučenin v mezihvězdných oblacích plynu. Experimentální studium reakcí provázejících jeho tvorbu a zánik za astrofyzikálně relevantních podmínek poskytuje důležité vstupy pro astrochemické modely a pro pochopení chemických procesů probíhajících v mezihvězdném prostoru., H3+, the simplest polyatomic ion, is a key precursor in many chemical reaction chains leading to the formation of complex molecules in interstellar molecular clouds. The experimental study of reactions leading to its formation and destruction at astrophysically relevant conditions gives important information for astrochemical models and enhanced our understanding of chemical processes occurring in the interstellar medium., Radek Plašil, Petr Dohnal, Štěpán Roučka, Juraj Glosík., and Obsahuje bibliografii