This work examines the chemical nature of extrasolar planetary systems, considering both the host star and any potential terrestrial planets located within the system. Extrasolar planetary host stars are found to be enriched over non-host stars in several r- and s-process elements. These enrichments, however, are in keeping with general galactic chemical evolution trends. This implies that host stars have not experienced any unusual chemical processing or pollution and that the observed enrichments are primordial in nature.When combined with detailed chemical models, the dynamical models of O'Brien et al. (2006) are found to produce terrestrial planets with bulk elemental abundances in excellent agreement with observed planetary values. This clearly indicates that the combination of dynamical and chemical modeling applied here is successfully reproducing the terrestrial planets of the Solar System to the first order. Furthermore, these planets are found to form with a considerable amount of water, negating the need for large amounts of exogenous delivery. Little dependence on the orbital properties of Jupiter and Saturn is observed for the main rock-forming elements due to the largely homogenous disk composition calculated.The same modeling approach is applied to known extrasolar planetary systems. Terrestrial planets were found to be ubiquitous, forming in all simulations. Generally, small (< 1ML) terrestrial planets are produced close to their host star with little radial mixing occurring. Planetary compositions are found to be diverse, ranging from Earth-like to refractory dominated and C-dominated, containing significant amounts of carbide material. Based on these simulations, stars with Solar elemental ratios are the best place to focus future Earth-like planet searches as these systems are found to produce the most Earthlike terrestrial planets which are located within the habitable zones of their systems and containing a significant amount of water. C-rich planets, although unusual, are expected to exist in >20% of known extrasolar planetary systems based on their host star photospheric compositions. These planets are unlike any body we have previously observed and provide an exciting avenue for future observation and simulation.

This study presents the development of an observing program to pursue the idea of looking for transiting exoplanets in eclipsing binary stars. The various kinds of orbits a planet might have in a binary system are explored. From this it is shown how to anticipate the possible orbits a planet might have in a given star system. The potential detectability of a planet in a binary system is also analyzed. Together these guidelines enable observers to rank targets by the likelihood that a detectable planet might exist in the system. The results of observations by a team at Ball State University of five binary star systems chosen with these guidelines are presented. / Department of Physics and Astronomy

Thesis (Ph. D.)--University of Washington, 2007. / Vita. Includes bibliographical references (p. 118-138).

Thesis (MS)--Montana State University--Bozeman, 2009. / Typescript. Chairperson, Graduate Committee: David R. Lageson. Includes bibliographical references (leaves 93-100).

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

Thesis (Ph. D.)--Ohio State University, 2005. / Title from first page of PDF file. Includes bibliographical references (p. 137-142).

Thesis (Ph. D.)--University of Texas at Austin, 2007. / Vita. Includes bibliographical references.

Thesis (Ph. D.)--University of Texas at Austin, 2006. / Vita. Includes bibliographical references.

Orientador: Tadashi Yokoyama / Banca: Nelson Callegari Junior / Banca: Rodney da Silva Gomes / Resumo: O sistema Plutão-Caronte é um par quase binário em estado de duplo sincronismo. Hoje sabe-se que Plutão possui cinco satélites: Caronte, Styx, Nix, Kerberos e Hydra, onde os últimos quatro são muito menores que Caronte. A origem mais plausível para o sistema Plutão-Caronte é a de um impacto de grandes proporções entre corpos de tamanhos similares, onde o impactador (que viria a ser Caronte) permanece quase intacto após o evento. Caronte iniciaria o movimento orbital próximo de Plutão (ex: a≈4 Rp) com ambos rotacionando rapidamente, como consequência da colisão mútua. Devido a intensa maré, suas distâncias irão evoluir e seus equadores (provavelmente desalinhados devido ao choque) irão também evoluir em consonância com seus respectivos spins. Alguns autores, por meio de um modelo bidimensional, tomando a maré modelada por Mignard (1980) e Peale (2007), usando dois métodos distintos, evoluíram Plutão-Caronte à partir deste cenário, reproduzindo os parâmetros orbitais e rotacionais atuais do sistema. Neste trabalho fazemos um estudo tridimensional, usando na parte rotacional as variáveis canônicas de Andoyer. Nesta abordagem, integramos a atitude de Plutão e Caronte por meio das equações de Hamilton, enquanto que a dinâmica translacional é feita classicamente via equações cartesianas de Newton. As contribuições dos torques, devidas às interações por efeito de maré entre Plutão e Caronte são inseridas nas equações de Hamilton. Como resultado mostramos o alinhamento dos equadores ... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: The Pluto-Charon system is almost a binary system in dual synchronous state. It is well known that Pluto has five satellites: Charon, Styx, Nix, Kerberos and Hydra, where the latter four are much smaller than Charon. The most plausible origin for the Pluto-Charon system is an oblique impact of great proportions between bodies with similar sizes. In this scenario, the impactor, which would later originate Charon, would remain almost intact after the collision. Initially the satellite would be revolving very close to Pluto (ex: a≈4Rp), with both bodies rotating very fast, as consequence of the mutual collision. The strong tidal effects, due to the initial approximation of both bodies combined with the fast rotation, expanded Charon's orbit, so as their equators aligned (probably misaligned due to the collision), in consonance with their respective spins. Some authors, using a two dimensional system and tidal forces modeled by Mignard (1980) and Peale (2007), with two distinct methods, evolved PlutoCharon from this scenario. They were able to reproduce the current orbital and rotational parameters of the system. In our work, a three-dimensional study was done, using the Andoyer's variable for the rotational problem. We integrated Pluto and Charon's atitude through Hamilton's equation, while the translational dynamics is calculated classically through Newton's cartesian equations. Torque's contributions due to tides raised on both Pluto and Charon are introduced in Hamilton's equ... (Complete abstract click electronic access below) / Mestre

Made available in DSpace on 2014-06-11T19:32:09Z (GMT). No. of bitstreams: 0 Previous issue date: 2013-03-06Bitstream added on 2014-06-13T21:03:28Z : No. of bitstreams: 1 costa_aif_dr_guara.pdf: 4600583 bytes, checksum: 3d77d0ac5008ebea1c760741e6b7ed43 (MD5) / Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) / O estudo da formação de planetas terrestres no Sistema Solar, é crucial para compre- endermos como outros sistemas planetários formam e também inferir as condições que poderiam ter influenciado a origem e evolução de vida na Terra. Esta Tese de douto- rado apresenta um estudo numérico da formação de planetas terrestres. Nosso objetivo principal é analisar o último estágio da formação desses planetas no Sistema Solar, em particular, a formação de Marte e a origem da água da Terra. Esses dois pontos têm intrigado cientistas ao longo de muitos anos. Enquanto que o planeta produzido ao redor de 1.5 UA é, em geral, muito mais massivo do que Marte, na grande parte das simulações, a origem da água da Terra é outro tema de intenso debate. Em vista disso, nós desenvol- vemos um cenário considerando uma depleção local de massa, no disco protoplanetário, a fim de analisarmos a origem da baixa massa de Marte, e também usamos um modelo composto para estudarmos a origem da água da Terra. Este trabalho apresenta um grande número de simulações numéricas explorando uma diversidade de parâmetros do sistema. Entre os principais podemos citar as variadas configurações de planetas gigantes, discos com diferentes perfis de densidade superficial de massa e modelos de distribuição de água. Nós também apresentamos um estudo dos efeitos de ressonâncias seculares nesses discos protoplanetários. Os principais resultados desses experimentos apontam a possibilidade da formação de planetas similares a Marte ao redor de 1.5 UA, especialmente, quando é considerado uma escala de depleção local, no disco protoplanetário, moderadamente alta (50-75%), localizada ao redor de 1.5 UA. Isto é observado juntamente com a formação de planetas do tipo Terra, em torno de 1 UA do Sol, com substanciais... / The study of terrestrial planet formation in the Solar System is crucial to understand how other planetary systems form and to infer the conditions that favored the origin and evolution of life on Earth. In this Thesis we present a numerical study of the accretion of terrestrial planets. Our main goal is study the late stage of the terrestrial planet accretion in the Solar System, especially the formation of Mars and the origin of Earth’s water. These two points have intrigued scientists for many years. Whereas the planet formed around Mars’ semimajor axis is, in general, much more massive than Mars, the origin of Earth’s water is a matter of intense debate. In view of that, we have developed a scenario considering a local depletion in the density of the protosolar nebula in order to analyze the low mass of Mars, and also explored a compound model of water distribution to study the origin of Earth’s water. We have carried out extensive numerical simulations of the formation of terrestrial planets in protoplanetary disks exploring a large variety of parameters of the system, as different giant planet configurations, surface density profiles and water distribution models. We also have presented a study of the effects of secular resonances on the evolution of these protoplanetary disks. Our main results point to the possibility of the formation of Mars-sized bodies around 1.5 AU, especifically when is considered a scale of the disk local mass-depletion moderately high (50-75%) around 1.5 AU, as well as Earth-sized planets can form around 1 AU with substantial amount of water. Regarding the origin of Earth’s water, we find that the compound model incorporating both the principal endogenous and exogenous theories, play an important role by... (Complete abstract click electronic access below)