Gravitational microlensing and the search for extrasolar planets

 

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dc.contributor.advisor Feast, Michael en_ZA
dc.contributor.advisor Menzies, John en_ZA
dc.contributor.author Mengistie, Getachew Mekonnen en_ZA
dc.date.accessioned 2014-11-28T09:51:43Z
dc.date.available 2014-11-28T09:51:43Z
dc.date.issued 2013 en_ZA
dc.identifier.citation Mengistie, G. 2013. Gravitational microlensing and the search for extrasolar planets. University of Cape Town. en_ZA
dc.identifier.uri http://hdl.handle.net/11427/9798
dc.description Includes bibliographical references. en_ZA
dc.description.abstract This project is aimed at tackling binary gravitational microlensing events. Since the early conception of gravitational lensing before Einstein’s General Theory of Relativity, physicists and astronomers of the early 18th century speculated that light, if treated as particle, can be affected by gravitational field. Gravitational Microlensing is defined as a phenomenon occurring when light coming from a distant (source) star is bent by the gravitational field of an intervening mass (lens) creating multiple image of the source which cannot be resolved. In this project, We applied a model for binary lens microlensing events. We analysed data obtained from different observatories: PLAXET, which includes SAAO, Sutherland, Canopus and Perth observatories, OGLE, Danish Telescope, LaSilla. For the observed microlensing target OGLE-2011-BLG-265, analysis of the data using the program supplied by Keith Horne, using different minimization schemes and algorithms, I found best fit model to be a binary lens with mass ratio q = 0.0042 and separation of components is found to be u = 1.034 where in this case the separation falls under an intermediate binary lens topology. Finally, the deviation from the point-source point-lens microlensing events on the light curve and small mass ratio suggested a planetary system. I also calculated the time, tp, that the source needs to cross the diameter of the planet Einstein Ring radius, which is related to the mass ratio, and is found to be 3.30 days. en_ZA
dc.language.iso eng en_ZA
dc.title Gravitational microlensing and the search for extrasolar planets en_ZA
dc.type Master Thesis
uct.type.publication Research en_ZA
uct.type.resource Thesis en_ZA
dc.publisher.institution University of Cape Town
dc.publisher.faculty Faculty of Science en_ZA
dc.publisher.department Department of Astronomy en_ZA
dc.type.qualificationlevel Masters
dc.type.qualificationname MSc en_ZA
uct.type.filetype Text
uct.type.filetype Image
dc.identifier.apacitation Mengistie, G. M. (2013). <i>Gravitational microlensing and the search for extrasolar planets</i>. (Thesis). University of Cape Town ,Faculty of Science ,Department of Astronomy. Retrieved from http://hdl.handle.net/11427/9798 en_ZA
dc.identifier.chicagocitation Mengistie, Getachew Mekonnen. <i>"Gravitational microlensing and the search for extrasolar planets."</i> Thesis., University of Cape Town ,Faculty of Science ,Department of Astronomy, 2013. http://hdl.handle.net/11427/9798 en_ZA
dc.identifier.vancouvercitation Mengistie GM. Gravitational microlensing and the search for extrasolar planets. [Thesis]. University of Cape Town ,Faculty of Science ,Department of Astronomy, 2013 [cited yyyy month dd]. Available from: http://hdl.handle.net/11427/9798 en_ZA
dc.identifier.ris TY - Thesis / Dissertation AU - Mengistie, Getachew Mekonnen AB - This project is aimed at tackling binary gravitational microlensing events. Since the early conception of gravitational lensing before Einstein’s General Theory of Relativity, physicists and astronomers of the early 18th century speculated that light, if treated as particle, can be affected by gravitational field. Gravitational Microlensing is defined as a phenomenon occurring when light coming from a distant (source) star is bent by the gravitational field of an intervening mass (lens) creating multiple image of the source which cannot be resolved. In this project, We applied a model for binary lens microlensing events. We analysed data obtained from different observatories: PLAXET, which includes SAAO, Sutherland, Canopus and Perth observatories, OGLE, Danish Telescope, LaSilla. For the observed microlensing target OGLE-2011-BLG-265, analysis of the data using the program supplied by Keith Horne, using different minimization schemes and algorithms, I found best fit model to be a binary lens with mass ratio q = 0.0042 and separation of components is found to be u = 1.034 where in this case the separation falls under an intermediate binary lens topology. Finally, the deviation from the point-source point-lens microlensing events on the light curve and small mass ratio suggested a planetary system. I also calculated the time, tp, that the source needs to cross the diameter of the planet Einstein Ring radius, which is related to the mass ratio, and is found to be 3.30 days. DA - 2013 DB - OpenUCT DP - University of Cape Town LK - https://open.uct.ac.za PB - University of Cape Town PY - 2013 T1 - Gravitational microlensing and the search for extrasolar planets TI - Gravitational microlensing and the search for extrasolar planets UR - http://hdl.handle.net/11427/9798 ER - en_ZA


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