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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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The light-curve solution of an eclipsing binary
Procházka, Ondřej ; Zasche, Petr (advisor) ; Wolf, Marek (referee)
The main aim of this work was the first detailed analysis of an eclipsing binary system V641 Aur. The complete light curve of this binary was obtained in three photometric filters, which were analyzed with the program PHOEBE. It is a double star with the orbital period of about 0.50487 day, whose both components are rather similar. Their individual spectral types are probably F6 and F8 (according to the temperatures), or F6 and F6 (as derived from masses). Both are orbiting on a circular orbit and despite their short period the system is a detached one and both components are still located on the main sequence. Moreover, thanks to the asymmetry of the light curve there was discovered a spot on the surface of the primary component, and the third light was not detected. For more detailed analysis higher accuracy of photometry and spectroscopy data are required.
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Design and construction of an interactive light sources panel
Žák, Martin ; Pavelka, Tomáš (referee) ; Škoda, Jan (advisor)
This semestral thesis deals with design and construction of the interactive light sources board and measurement of various parameters of those light sources. Using the given requirements, a solution is worked out (construction materials, behaviour, design, wiring etc. are given). Based on this, the interactive board was also constructed and put into operation. The thesis is also focused on the given light sources themselves (incandescent light bulbs, halogen lamps, compact fluorescent lamps, fluorescent tubes and LED lamps) and their measurement results are presented.
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