Thesis (Ph.D.) - University of St Andrews, May 2007.

Thesis (Ph.D.) - University of St Andrews, November 2009.

We present results from 30 nights of observations of the intermediate-age Solar-metallicity open cluster NGC 7789 with the WFC camera on the INT telescope in La Palma. From ~900 epochs, we obtained lightcurves and Sloan r' - i' colours for ~33000 stars, with ~2400 stars with better than 1% precision. We find 24 transit candidates, 14 of which we can assign a period. We rule out the transiting planet model for 21 of these candidates using various robust arguments. For 2 candidates we are unable to decide on their nature, although it seems most likely that they are eclipsing binaries as well. We have one candidate exhibiting a single eclipse for which we derive a radius of 1.81+/0.09- Three candidates remain that require follow-up observations in order to determine their nature. Monte Carlo simulations reveal that we expected to detect ~2 transiting 3d to 5d hot Jupiter planets from all the stars in our sample if 1% of stars host such a companion and that a typical hot Jupiter radius is similar to that of HD 209458b. Our failure to find good transiting hot Jupiter candidates allows us to place an upper limit on the 3d to 5d hot Jupiter fraction of 2.6% for all stars at the 1% significance level, and similar useful limits on the hot Jupiter fraction of the different star types in our sample.

Au cours des 15 dernières années, plus de 500 exoplanètes ont été détectées, révélant l'existence de systèmes souvent très différents du nôtre. Ces découvertes ont profondément affecté notre compréhension des mécanismes de formation des systèmes planétaires et de leur évolution dynamique. Aujourd'hui, les deux défis principaux sont d'estimer l'abondance des planètes jusqu'aux masses telluriques et d'effectuer la transition de la détection vers la caractérisation des exoplanètes. Cette thèse apporte une contribution sur les deux aspects, détection d'exoplanètes par microlentilles gravitationnelles et de molécules dans les atmosphères. Les microlentilles gravitationnelles ont permis de détecter 20 exoplanètes (publiées ou en cours de publication), incluant deux super-Terres de 3.2 et 5.5 $M_\oplus$. Bien que ce nombre soit modeste, cette technique permet l'exploration de systèmes inaccessibles via d'autres methodes, ayant son maximum de sensibilité au-delà de la limite des glaces. Nous détaillons tout d'abord l'analyse d'un évènement de haute amplification et sa sensibilité à la présence potentielle d'une planète. Avec une étoile à 5.5 kpc du système solaire, un compagnon de type terrestre orbitant à quelques UA aurait pu être détecté. Cette analyse d'efficacité de détection a contribué à une étude plus large visant à estimer l'abondance de planètes au sein de la Galaxie, montrant que les Saturne glacées sont abondantes. Nous traitons ensuite d'un évènement impliquant une planète massive orbitant une étoile naine et discutons de la faible probabilité d'existence d'un tel système selon les théories de formation planétaire du modèle d'accrétion de coeur. La prise en compte d'effets du second ordre dans la modélisation de cet évènement, doublée d'une analyse bayesienne à partir des distributions de vitesse et de luminosité des étoiles de la Galaxie, a permis de contraindre la dynamique du système. Enfin, la découverte d'une planète de type Neptune dont j'ai participé à la détection est présentée. Sur le thème des atmosphères planétaires, nous présentons l'analyse du Jupiter chaud HD209458b basée sur des mesures de transits primaires par Spitzer dans l'infrarouge. J'ai développé un algorithme de type MCMC adapté aux courbes de transits afin d'estimer les paramètres physiques et orbitaux de la planète. Ces paramètres constituent alors des données d'entrée pour les modèles d'atmosphère planétaire. Le spectre en transmission de HD209458b est dominé par l'absorption de vapeur d'eau.

Exoplanets that transit nearby M dwarfs allow us to measure the sizes, masses, and atmospheric properties of distant worlds. Between 2008 and 2013, we searched for such planets with the MEarth Project, a photometric survey of the closest and smallest main-sequence stars. This thesis uses the first planet discovered with MEarth, the warm 2.7 Earth radius exoplanet GJ1214b, to explore the possibilities that planets transiting M dwarfs provide. / Astronomy

No description available.

Desde a virada do século, espetáculos da Broadway, em Nova York, passaram a ser largamente produzidos em São Paulo. No intervalo de pouco mais de uma década, um sistema organizado de produção de musicais instaurou-se na capital paulista. Esta tese tem como objetivo investigar alguns trânsitos teatrais entre essas cidades no início do novo milênio. A pesquisa analisa a maneira pela qual intérpretes atrizes e atores produziam, atualizavam e negociavam as diferenças nos bastidores. O trabalho adotou duas grandes estratégias. Primeiro, realizei uma investigação documental baseada em fontes primárias capaz de identificar os condicionantes sociais, econômicos e simbólicos que contribuíram para tornar os musicais teatralmente verossímeis, economicamente rentáveis e socialmente desejados em São Paulo. Concomitantemente, desenvolvi uma pesquisa de campo em escolas de teatro musical em São Paulo e Nova York, onde verifiquei que, no dia a dia do aprendizado, a interpretação era fundamental para expressar o mundo emotivo interno em cena. Além disso, professores ensinavam que artistas precisavam reconhecer os tipos que os seus corpos lhes permitem ser: quem teria o perfil para ser protagonista em certos espetáculos e quem não teria. Também realizei entrevistas com atrizes e atores brasileiros que viajaram para os Estados Unidos com a intenção de se especializarem como intérpretes. Aos poucos, ficou evidente como sujeitos adotavam uma gramática que qualificava os musicais ora como universais ora como particulares. Por um lado, as emoções entre as pessoas seriam universalmente compartilhadas nas duas cidades, permitindo o trânsito das peças. Por outro lado, os corpos de artistas eram particularmente diferenciados e nem todos tinham perfil para o trabalho. O itinerário dessas peças entre as cidades foi pavimentado por um conjunto intrincado de argumentos que incluía a potencialidade pedagógica das técnicas cênicas, as vantagens econômicas das produções, a comunhão global de emoções e a conquista de um sonho individual de artistas. Em paralelo, em São Paulo, os trajetos sofriam deslocamentos, adaptações, contestações e disputas. Dessa forma, investigo como discursos e práticas acerca da particularidade e da universalidade foram produzidos, reproduzidos, ressignificados, negociados, e, por vezes, recusados pelos sujeitos. As diferenças e semelhanças apareciam nas relações estabelecidas durante as diversas circunstâncias observadas. A pergunta analítica que atravessa toda a tese é: como as diferenças e as semelhanças apareciam nos trânsitos teatrais entre São Paulo e Nova York? / Since the turn of the century, Broadway shows in New York City have come to be largely produced in São Paulo. In less than a decade, an organized system of musical production was established in the capital of the Brazilian State of São Paulo. This thesis purpose is to investigate some theatrical traffic between these cities in the beginning of the new millennium. The research analyses actress and actors way of producing, updating and negotiating the concept of difference in the backstage. The work has adopted two major strategies. First, I pursued a documental investigation based on primary sources to identify the social, economic and symbolic environment that allowed this to become viable. Simultaneously, I have endeavored field research at musical theater schools in São Paulo and New York City. I concluded that, in the daily learning, acting was essential to express the inner emotional world portrayed in scene. Furthermore, teachers instructed artists to recognize the types their bodies allowed them to be: who could be the lead in certain shows and who could not. I have also conducted interviews with Brazilian actress and actors that had travelled to the United States pursuing a career. Slowly, it became evident how subjects adopted a certain grammar that sometimes qualified musicals as universal, while at other times understood them as particular. On one hand, emotions were universally shared between the two cities allowing the traffic of plays. On the other, the performers bodies displayed particular differences and not all embodied the necessary type for the job. An intricate ensemble of arguments that included pedagogic potential of theatrical techniques, economic advantages of productions, global communion of emotions and the artists conquer of their individual dream cemented the plays itinerary between the cities. In parallel, in São Paulo, this discourse suffered displacement, adaptation, defiance and dispute. Thus, I investigate how speech and practices regarding particularity and universality have been produced, reproduced, re-significated, negotiated and, at times, rejected by subjects. Differences and similarities have surfaced in relationships established during the many circumstances observed by this author. The analytical question for the entire thesis is: how differences and similarities emerge in theatrical traffic between São Paulo and New York City?

Grâce à la spectroscopie des vitesses radiales, on connaît en 2003 plus d'une centaines d'exoplanètes géantes autour d'étoiles de type solaire. Les limites de cette technique poussent à utiliser d'autres méthodes pour caractériser complètement les planètes connues, détecter des planètes de taille terrestre, et accéder à des informations statistiques sur une grande population d'objets. Cette thèse porte sur deux de ces techniques complémentaires : d'une part la photométrie des transits et d'autre part l'interférométrie infrarouge à très longue base. La photométrie des transits a été étudiée dans le cadre de la mission spatiale COROT : on a mis en oeuvre un algorithme de détection par filtrage adapté afin de déterminer (i) l'efficacité de détection de l'instrument pour différentes distributions orbitales des planètes, et (ii) la répartition des détections en fonction du type spectral et de la magnitude de l'étoile hôte. En outre, on a étudié l'utilisation des canaux photométriques de COROT pour discriminer les fausses détections et pour réduire la part du bruit de variabilité stellaire. Un traitement global des mesures par interférométrie à très longue base et par spectroscopie permet la caractérisation complète des systèmes doubles. On a appliqué ce traitement à des observations réelles d'étoiles binaires spectroscopiques, puis on a étudié la faisabilité d'observations de couples du type de 51 Pegasi. Par ailleurs, on a contribué à l'effort vers la très haute précision en interférométrie infrarouge par la réalisation d'un catalogue d'étoiles-étalons, et par la caractérisation instrumentale d'un prototype de fibre monomode à 10 µm, un composant essentiel pour les missions spatiales dédiées aux exoplanètes telluriques comme Darwin/TPF.

Made available in DSpace on 2014-12-17T13:54:54Z (GMT). No. of bitstreams: 1 francimarioVS.pdf: 1346865 bytes, checksum: 810543738183e622bbb82dcd04dc6143 (MD5) Previous issue date: 2007-03-23 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior / The present Master?s dissertation aims to study the practices of the rezadeiras, Brazilian women healers, through an anthropological perspective. Special attention will be given to the understanding of these practices as a dynamic process in relation to those women who heal in Cruzeta (Serid?, Rio Grande do Norte), where is located our ethnographic research. For this research, twenty four rezadeiras were contacted and colaborated with our work plan. Among them, two were pentecostal rezadeiras and another one was member of the Jurema cult, an afro-brazilian religious cult. Similarities among these women healers were perceived in the research process, mostly in terms of their learning process and the use of certain objects and ritual techniques. However, apparent differences among them gave us the chance for understanding and reflecting on the actual heterogeneity of this world of specialists. Furthermore, i tried to capture the relations between the rezadeiras and the therapeutic practices from health professionals or the religious practices of religious leaders (Catholic, pentecostal, etc). It is possible to ascertain about the complementarity between therapeutic practices from different cultural logics. This complementarity is also perceived through the religious interchanges and transits among different healers, including those who have different religious beliefs. In this work, rituals are also described and they are a crucial factor to the understanding of this particular religious and therapeutic practice conducted by women. Following these ideas, our basic aim is to understand how the rezadeiras make interpretations about health and illness, specially those ones which are particular associated with their practices, the so called "doen?as de rezadeiras" / A presente disserta??o aborda as pr?ticas das rezadeiras a partir de uma perspectiva antropol?gica, cuja aten??o estar? voltada para a compreens?o desta pr?tica como um processo din?mico, tendo Cruzeta (Serid?, RN) como contexto de pesquisa etnogr?fica. Para a realiza??o da pesquisa, contei com a colabora??o de vinte e quatro rezadeiras. Dentre elas, duas eram rezadeiras evang?licas e uma outra que era adepta do culto da jurema. As semelhan?as existentes entre as rezadeiras eram vis?veis, sobretudo em rela??o ao processo de aprendizagem e ao uso de certos objetos e t?cnicas rituais. No entanto, as diferen?as existentes possibilitaram a realiza??o de uma reflex?o acerca da pr?pria heterogeneidade do universo de especialistas. Al?m disso, tentei captar a rela??o das rezadeiras com as pr?ticas terap?uticas dos profissionais da biomedicina e as pr?ticas religiosas do padre e do pastor evang?lico. Pode-se constatar a complementaridade entre pr?ticas terap?uticas com l?gicas diferentes. Essa complementaridade tamb?m ? percebida a partir dos tr?nsitos religiosos compartilhados pelas rezadeiras evang?licas. Presente neste trabalho, a descri??o dos rituais tamb?m ? um fator primordial para a compreens?o das pr?ticas religiosa e terap?utica realizadas por estas mulheres. Diante do exposto, o nosso objetivo ? procurar entender como as rezadeiras interpretam a sa?de e a doen?a, sobretudo levando em considera??o as doen?as ditas de rezadeiras

Les Jupiters chauds sont des exoplanètes si proches de leur étoile que leur atmosphère peut perdre du gaz par échappement hydrodynamique. Les géantes gazeuses qui transitent sont un excellent moyen de comprendre ce processus, mais il faut étudier d'autres types de planètes pour déterminer son impact sur la population exoplanétaire. Cette thèse propose d'utiliser la spectroscopie du transit pour observer l'atmosphère de plusieurs planètes, étudier leurs propriétés et caractériser l'échappement hydrodynamique. Des raies de l'ultraviolet observées avec le télescope Hubble sont analysées avec le modèle numérique de la haute atmosphère que nous avons développé. Grâce à la raie Ly-? nous mettons en évidence les interactions énergétiques et dynamiques entre l'atmosphère des Jupiters chauds HD209458b et HD189733b et leurs étoiles. Nous étudions la dépendance de l'échappement à l'environnement d'une planète et à ses propriétés physiques, en observant une super-Terre et un Jupiter tiède dans le système 55Cnc. Grâce à des observations de HD209458b nous montrons que les raies du magnésium permettent de sonder la région de formation de l'échappement. Nous étudions le potentiel de la spectroscopie du transit dans le proche UV pour détecter de nouveaux cas d'échappement. Ce mécanisme est favorisé par la proximité d'une planète à son étoile, ce qui rend d'autant plus important la compréhension des processus de formation et de migration, qui peuvent être étudiés par l'alignement d'un système planétaire. Grâce à des mesures des spectrographes HARPS-N et SOPHIE nous étudions les alignements de 55Cnc e et du candidat Kepler KOI-12.01, dont nous cherchons aussi à valider la nature planétaire. / Hot Jupiters are exoplanets so close to their star that their atmosphere can lose gas because of hydrodynamic escape. Transiting gaseous giants are an excellent way to understand this mechanism, but it is necessary to study other types of planets to determine its impact on the exoplanetary population. This thesis aims at using transit spectroscopy to observe the atmosphere of several exoplanets, to study their properties and to contribute to the characterization of hydrodynamic escape. UV lines observed with the Hubble telescope are analyzed with the numerical model of upper atmospheres we developed. Using the Ly-? line we identify energetic and dynamical interactions between the atmospheres of the hot Jupiters HD209458b and HD189733b and their stars. We study the dependence of the escape on the environment of a planet and on its physical properties, through the observation of a super-Earth and a warm Jupiter in the 55 Cnc system. Using observations of HD209458b, we show that magnesium lines are a window on the region of formation of hydrodynamic escape. We study the potential of transit spectroscopy in the near-UV to detect new cases of atmospheric escape. This mechanism is fostered by the proximity of a planet to its star, which makes it even more important to understand the formation and migration processes that can be traced in the alignment of a planetary system. Using measures from the spectrographs HARPS-N and SOPHIE we study the alignments of 55 Cnc e and the Kepler candidate KOI 12.01, whose planetary nature we also seek to validate.