Feasibility of transit photometry of nearby debris discs

Dust in debris discs is constantly replenished by collisions between larger objects. In this paper, we investigate a method to detect these collisions. We generate models based on recent results on the Fomalhaut debris disc, where we simulate a background star transiting behind the disc, due to the proper motion of Fomalhaut. By simulating the expanding dust clouds caused by the collisions in the debris disc, we investigate whether it is possible to observe changes in the brightness of the background star. We conclude that in the case of the Fomalhaut debris disc, changes in the optical depth can be observed, with values of the optical depth ranging from $10^{-0.5}$ for the densest dust clouds to $10^{-8}$ for the most diffuse clouds with respect to the background optical depth of $\sim1.2\times10^{-3}$.Comment: 19 pages, 15 figures, accepted for publication in MNRA

Program for digital watermarking of image data

Tento projekt je zaměřen na současně použivané metody vytváření digitálních vodoznaků v obrazech. Cílem práce je studie zaměřená na základní vodoznakové techniky, principy vkládání vodoznaků do obrazů a na možnosti využití těchto metod na ochranu autorských práv. V rámci bakalářské práce byla ověřena možnost vkládání vodoznaku do obrazu s využitím programu Matlab.This project is specialized on the method generation digital watermark in pictures. Aim work is study bent on basic watermark techniques, principles embedding of watermark to the pictures and on possibilities usage these methods on protection author's rights. In terms of project was tested possibility embedding of watermark to the picture with usage programme Matlab.

Solar radiation simulator

Tato diplomová práce je zaměřena na vlastnosti přímého slunečního záření, difúzního záření a jejich využití pro solární systémy. Cílem práce je porovnat jednotlivé zdroje světla s tímto zářením a výběr zdroje pro simulátor slunečního záření. Dále pak vytvořit přípravek pro měření homogenity rozložení slunečního záření a realizovat solární simulátor.This master's thesis is focused on properties of direct solar radiation, diffuse radiation and their usage in solar systems. Goal of this paper is to compare the different sources of light with the radiation and selection source for the solar radiation simulator, followed by a measuring device for homogeneous distribution of solar radiation and implemantation of solar simulator.

STIS Coronagraphic Imaging of Fomalhaut: Main Belt Structure and the Orbit of Fomalhaut b

We present new optical coronagraphic data of the bright star Fomalhaut obtained with the HST in 2010/2012 using STIS. Fomalhaut b is recovered at both epochs to high significance. The observations include the discoveries of tenuous nebulosity beyond the main dust belt detected to at least 209 AU projected radius and a ~50 AU wide azimuthal gap in the belt northward of Fom b. The morphology of Fomalhaut b appears elliptical in the STIS detections. We show that residual noise in the processed data can plausibly result in point sources appearing extended. A MCMC analysis demonstrates that the orbit of Fom b is highly eccentric, with e=0.8+/-0.1, a=177+/-68 AU, and q = 32+/-24 AU. Fom b is apsidally aligned with the belt and 90% of allowed orbits have mutual inclination 36 deg or less. Fomalhaut b's orbit is belt-crossing in projection, but only 12% of possible orbits have nodes within a 25 AU wide belt annulus (133-158 AU). The high e invokes a dynamical history where Fom b may have experienced a significant dynamical interaction with a hypothetical planet Fomalhaut c, and the current orbital configuration may be relatively short-lived. The new value for the periastron distance diminishes the Hill radius of Fom b and any weakly bound satellite system surrounding a planet would be sheared and dynamically heated at periapse. We argue that Fom b's minimum mass is that of a dwarf planet in order for a circumplanetary satellite system to remain bound to a sufficient radius from the planet to be consistent with the dust scattered light hypothesis. Fom b may be optically bright because the recent passage through periapse and/or the ascending node has increased the erosion rates of planetary satellites. In the coplanar case, Fomalhaut b will collide with the main belt around 2032, and the subsequent emergent phenomena may help determine its physical nature.Comment: 49 Pages, 33 Figures, 5 Tables; Submitted to ApJ, Dec. 31, 201