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The light curves of eclipsing binaries
Korda, David ; Zasche, Petr (advisor) ; Wolf, Marek (referee)
New CCD photometric observations of ten short-period LMB (Low Mass Binaries) were carried out. Data were obtained using 65 cm telescope in Ondřejov in the filters I, R and V from 2014 to 2016. Light curves were analysed using the program PHOEBE. The obtained masses and radii of the stars were compared with the theoretical mass-radii relation. There arises that the short-period binaries have the radii of about 4 % larger than the theoretical prediction from the stellar evolution models. Powered by TCPDF (www.tcpdf.org)
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Technology of pouring LED strips with epoxy materials
Rudy, Veronika ; Krejčí, Miroslav (referee) ; Píška, Miroslav (advisor)
The thesis deals with the pouring of epoxy materials over LED strips. The research part contains an introduction to photometry and summarizes the types of potting compounds along with their characteristics. The practical part delves into the effect different amount of pigment has on the photometric properties. This is assessed based on verified measurements performed with the help of a goniophotometer on samples with different amounts of pigment, which were created using an integration sphere. Furthermore, a brightness analysis and a long-term outdoor test were performed.
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The light curves of eclipsing binaries
Korda, David ; Zasche, Petr (advisor)
New CCD photometric observations of ten short-period LMB (Low Mass Binaries) were carried out. Data were obtained using 65 cm telescope in Ondrejov in the filters I, R and V from 2014 to 2016. Light curves were analysed using the program PHOEBE. The obtained masses and radii of the stars were compared with the theoretical mass-radii relation. There arises that the short-period binaries have the radii of about 4 % larger than the theoretical prediction from the stellar evolution models. 1
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Problems of the mirror shutter in the LED module of the headlight
Ettler, Jan ; Hlaváček, Martin (referee) ; Kalivoda, Milan (advisor)
This bachelor thesis deals with methods of attaching the mirror shutter in LED modules in headlamps. The aim is to compare three methods of attachment which are used in one of the platform variants. The following are the methods of attachment, followed by the description of the light sources and functions of the LED modules; they are: riveting, hot stamping and fixation with clips. Risk associated with the assembly of mirror shutter into the light source are analysed via FMEA analysis, including also measures and actions for risk reduction – implementation of lighting of produced light sources in a special jig in the light laboratory. Vibrations tests were carried out to find out the influence of vibration on the mirror shutter in LED modules in the traffic. The tests revealed that even if the clip is incorrectly fixed (not attached to the end position) it does not affect the functionality of the module.
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Industrial Tester for Photometric Values of LED diodes Used in Automotive Signal Lighting
Gaži, Dominik ; Froehling, Kenneth (referee) ; Baumgartnerová, Alena (advisor)
V posledních letech zažili světlomety v autech obrovský technický rozvoj, který se podílel na jejich současné složitosti. Aby řidiči i zákazníci byli spokojeni, je využíváno různých technologií pro neustálé dosahování účinnějších a bezpečnějších světelných zdrojů. Společnosti usilují o minimalizaci ztrát ve výrobě ve snaze šetřit životní prostředí a konat ekonomicky. Tato práce se zabývá výzkumem osvětlovací techniky a návrhem jednoduchého a efektivního zařízení pro testovaní chyb LED plošných obvodů ve světlometech, to vše za účelem minimalizace strat. Dalším cílem je výzkum možností konstrukce takového zařízení z technologického hlediska.
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Distance to the Magellanic clouds
Kulich, Matúš ; Zasche, Petr (advisor) ; Korčáková, Daniela (referee)
Twelve eclipsing binary systems from the region of the Large Magellanic Cloud have been studied in this thesis in order to calculate the distance. The photometric data come from the OGLE survey carried out at the Las Campanas Observatory in Chile and the spectroscopic data come from other papers where they had already been partially ana- lyzed for other purposes. From these data, the light curves and the radial velocity curves of these systems have been constructed and analyzed using the PHOEBE soft- ware, in which the physical parameters and the absolute magnitudes of their individual components have been determined by the method of synthetic curves. By comparing them to the observed apparent magnitudes in I-band deduced from the light curves and taking into account the bolometric corrections and the V-I indices, the distance modu- lus of the Large Magellanic Cloud could be determined to be 18.59 ± 0.4 mag, which fairly corresponds to the quite familiar results determined by using this and other meth- ods in various research papers. However, in order to determine the distance modulus more accurately, it would be necessary to use accurate, much more complex models of stellar atmospheres and not simply rely on the general relations of the main-se- quence stellar parameters, which exhibit quite a large variance.
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Measurement of photometric parameters of light sources for interactive panel
Vágner, Richard ; Štěpánek, Jaroslav (referee) ; Škoda, Jan (advisor)
This bachelor thesis deals with measurment of various photometric parameters of light sources designated for interactive board located in the Laboratory of Light VUT FEKT. There is described procedure and processing of photometric and electrical parameters of light sources (incandescent light bulbs, halogen lamps, compact fluorescent lamps, fluorescent tubes and LED lamps). Also there is presented processing method of designing cards that will contain mentioned parameters.
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The light curves of eclipsing binaries
Korda, David ; Zasche, Petr (advisor)
New CCD photometric observations of ten short-period LMB (Low Mass Binaries) were carried out. Data were obtained using 65 cm telescope in Ondrejov in the filters I, R and V from 2014 to 2016. Light curves were analysed using the program PHOEBE. The obtained masses and radii of the stars were compared with the theoretical mass-radii relation. There arises that the short-period binaries have the radii of about 4 % larger than the theoretical prediction from the stellar evolution models. 1
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CCD photometry of variable objects in nearby galaxies
Kára, Jan ; Wolf, Marek (advisor) ; Zasche, Petr (referee)
The work concerns the study of variable stars in the Small Magellanic Cloud with use of time series of photometric images of star field NGC 330, which were obtained by the 1,54-m Danish telescope at the observatory La Silla in Chile during years 2012 - 2016. The aim of this work is to produce light curves of variable stars a to determine their period of variability assuming the variations are periodical. For some stars data from earlier published papers were used, which led to the coverage of longer period of time and therefore to the improvement of the accuracy of the period determination. The work lists summary of some of the types of variable stars and of mechanisms causing their variability. The work focus mainly on cepheids, which can be used to determine distances in the Universe thanks to the relation between their absolute magnitude and period of pulsation.
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The light curves of eclipsing binaries
Korda, David ; Zasche, Petr (advisor) ; Wolf, Marek (referee)
New CCD photometric observations of ten short-period LMB (Low Mass Binaries) were carried out. Data were obtained using 65 cm telescope in Ondřejov in the filters I, R and V from 2014 to 2016. Light curves were analysed using the program PHOEBE. The obtained masses and radii of the stars were compared with the theoretical mass-radii relation. There arises that the short-period binaries have the radii of about 4 % larger than the theoretical prediction from the stellar evolution models. Powered by TCPDF (www.tcpdf.org)
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