Este trabalho tem como objetivo abordar a modelagem da formação e migração de um núcleo sólido planetário . Para isso, foi utilizado um modelo de acreção de planetesimais, baseado no trabalho de Inaba et al. (2000), no qual a taxa de acreção média depende da inclinação e excentricidade dos planetesimais, obtidas através da situação de equilbrio entre a interação com o protoplaneta e o arrasto do gás (Fortier et al., 2013). Para complementar esse cenário, foi includa a migração de tipo I, que ocorre devido à interação do planeta com o disco de gás. O modelo analtico que descreve essa migração teve como base o trabalho de Tanaka et al. (2002). O perfil de densidade de gás e sólidos foi obtido com base em três modelos diferentes para o disco. O primeiro é o modelo clássico da Nebulosa Solar, no qual o perfil de densidade decai com r 3/2 ; o segundo é um modelo hbrido, que utiliza medidas observacionais da densidade superficial do gás (Andrews e Williams, 2005) e uma estimativa analtica para a densidade volumêtrica do gás; por fim, o terceiro modelo é um disco de acreção que utiliza a parametrização de Shakura e Sunyaev (1973) com constante. Com o uso desses três perfis diferentes para o disco, foi possvel explorar a variação dos parâmetros livres do modelo e a possibilidade de formação de núcleos sólidos, da ordem de 10M Terra , num tempo menor que o tempo de vida do disco, estimado como menor que 10 × 10^6 anos. Em geral, a migração de tipo I é muito rápida, de modo que o protoplaneta cai na estrela antes mesmo de adquirir massa suficiente para iniciar a acreção de gás. No entanto, a análise revelou, para o disco hbrido, a possibilidade de se obter massas próximas de 10MTerra , num tempo da ordem de 2 × 10^6 anos, em distâncias de até 3.5 UA. Conclui-se, então, que modelos de acreção mais completos, assim como a obtenção deperfis de densidade de gás e sólidos dos discos protoplanetários mais coerentes, podem explicar a formação de núcleos sólidos num tempo hábil para a formação de planetas gigantes, sem a necessidade de fatores numéricos que reduzam a taxa de migração de tipo I. / The aim of this paper is to model the planetary formation and migration of a solid core. Therefore, it was used a model of planetesimal accretion, based on the paper of Inaba et al. (2000), in which the average accretion tax depends on the inclination and eccentricity of that planetesimals. These parameters were obtained through the balance situation between the interaction with the protoplanet and gas draft (Fortier et al., 2013). In order to complete this scenario, the migration type I, which occurs due to an interaction of the planet with the gas disc, was included. The analytical model that describes this migration has its basis on (Tanaka et al., 2002). The density of solids and gas profile was based on three different models for the disc. The first one is a classical of Nebulosa Solar, in which the density profile varies r^3/2 , the second is a hybrid model that uses observational measures of the gas superficial density (Andrews et al., 2010) and an analytical formula for the gas volumetric density; at last, the third model is an accretion disc which uses the parameterization of (Shakura e Sunyaev, 1973) with constant. Using these three different disc profiles, it was possible to explore the variation of the model free parameters and the possibility of the solid cores formation with 10M Earth within time smaller than 10 × 10^6 years, which is the estimated limit lifetime of the disc. In general, migration type I is very fast, so that the protoplanet falls on the star before acquiring enough mass to begin the gas accretion. However, the analysis has revealed, for the hybrid disc, the possibility to obtain masses up to 10MEarth within time 2 × 10^6 , for distance up to 3.5 AU. In conclusion, more complete models of accretion as well as the more coherent density gas and solid profiles of the protoplanet obtained may explain the formation of solid coreswithin a useful time for the giant planets formation, not using numerical factors that reduce the migration type I tax.

Planet rendering plays an important role in universe visualization and geographic visualization. The recent tools and methods allow better data acquisition, usually with very high resolution. However in computer graphics, there is always the limitation on the resolution of geometry and texture due to numerical imprecision. Not many applications can handle high resolution data effectively. This thesis introduces, Implicit Surface Scene, a level of detail scene management inspired by dynamic coordinate system and SCALEGRAPH™ which change over time depending on the current camera position relative to the planet surface. Our method is integrated into Uniview and allows Uniview to render high resolution planet geometry with dynamic texture composition and with a surface positioning system that does not suffer from precision issue.

Thèse : Sciences mathématiques : Paris, Faculté des sciences : 1854. / Thèse de mécanique : Mouvement dans un milieu résistant d'un point matériel attiré par un centre fixe, p. [3]-34. Thèse d'astronomie : De la figure de l'anneau de Saturne, p. [35]-52. Titre provenant de l'écran- titre.

Thèse : Sciences : Paris : 1855. / Thèse d'astronomie, 78 p. at end, has title: Application de la méthode de M.-Hamilton au calcul des perturbations de Jupiter. Titre provenant de l'écran-titre.

Thesis (M.S.)--Virginia Polytechnic Institute and State University, 1999. / Cover title. Computer printout. Abstract. Includes bibliographical references (p. [103]-112). Available electronically via Internet.

Thesis (Ph. D.)--University of California, San Diego, 2001. / Vita. Includes bibliographical references.

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Detection of the emission from the secondary component in a binary system can be extremely challenging, but equally rewarding. In the case of intermediate to high-mass binaries, detection of close companions can inform formation theories. In the extreme low mass-ratio case, where the secondary component is in fact a planet, detection of the emission in high resolution spectroscopy can be used to determine the true planet mass. In this thesis, we describe a technique to detect the thermal emission from the secondary component of a low mass-ratio binary system. We apply this technique to archived observations of early B-type stars using VLT/CRIRES, and simulate future observations of planetary systems with IGRINS, a near-infrared spectrograph being built now. / text

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