The recent discovery of objects near the 5:1 Neptune resonance prompts the study of the size, structure, and surface properties of this population to determine if these parameters are consistent with a ‘Nice model’ type evolution of the outer Solar System. Previous TNO discovery surveys have primarily targeted the ecliptic plane, where discovery of high inclination objects such as the 5:1 resonators is unlikely, and theoretical work on the evolution of the outer Solar System has focused on structure in and around the main Kuiper belt and largely ignored the distant resonant TNOs. I tracked these objects for several semesters, measured their positions accurately, and determined precise orbits. Integrating these orbits forward in time revealed that three objects are 5:1 resonators, and one object is not resonant but may have been resonant in the past. I constrained the structure of the 5:1 resonance population based on the three detections and determined that the minimum population in this resonance was much larger than expected, 1900(+3300,−1400) with H < 8. I compared this large population with the orbital distribution of TNOs resulting from a Nice model evolution and determined that the population in the real 5:1 resonance is ~20–100 times larger than the model predicts. However, the structure of the 5:1 resonance in this model was consistent with the orbital distribution I determined based on the detections. The orbital distribution of the scattering population in the Nice model is consistent with other models and survey results, leading to the conclusion that the 5:1 resonance cannot be a steady state transient population produced via resonance sticking from the scattering objects. To test the origin of the 5:1 resonators, I measured the objects’ surface colors in multiple wavelength ranges and compared their surface reflectance to TNOs from a large color survey, ColOSSOS. The 5:1 resonators have a consistent selection criteria to the TNOs from the ColOSSOS survey, so these samples have known selection biases and can be usefully compared to each other. The surfaces of the three 5:1 resonators showed three different spectral reflectance shapes, indicating that these three objects do not share a common formation location. The surface properties and orbital distribution of current 5:1 resonators are consistent with the remnant of a large captured population, partially resupplied by the scattering objects. However, the scattering event which produced this large 5:1 population remains unexplained. / Graduate

We report the discovery of the minor planet 2013 SY99 on an exceptionally distant, highly eccentric orbit. With a perihelion of 50.0. au, 2013 SY99' s orbit has a semimajor axis of 730 +/- 40. au, the largest known for a high-perihelion trans-Neptunian object (TNO), and well beyond those of (90377) Sedna and 2012 VP113. Yet, with an aphelion of 1420 +/- 90. au, 2013 SY99' s orbit is interior to the region influenced by Galactic tides. Such TNOs are not thought to be produced in the current known planetary architecture of the solar system, and they have informed the recent debate on the existence of a distant giant planet. Photometry from the Canada-France-Hawaii Telescope, Gemini North, and Subaru indicate 2013 SY99 is similar to 250. km in diameter and moderately red in color, similar to other dynamically excited TNOs. Our dynamical simulations show that Neptune's weak influence during 2013 SY99' s perihelia encounters drives diffusion in its semimajor axis of hundreds of astronomical units over 4. Gyr. The overall symmetry of random walks in the semimajor axis allows diffusion to populate 2013 SY99' s orbital parameter space from the 1000 to 2000. au inner fringe of the Oort cloud. Diffusion affects other known TNOs on orbits with perihelia of 45 to 49. au and semimajor axes beyond 250. au. This provides a formation mechanism that implies an extended population, gently cycling into and returning from the inner fringe of the Oort cloud.

For centuries, an orderly view of planetary system architectures dominated the discourse on planetary systems. However, there is growing evidence that many planetary systems underwent a period of upheaval, during which giant planets "migrated" from where they formed. This thesis addresses a question key to understanding how planetary systems evolve: is planetary migration typically a smooth, disk-driven process or a violent process involving strong multi-body gravitational interactions? First, we analyze evidence from the dynamical structure of debris disks dynamically sculpted during planets' migration. Based on the orbital properties our own solar system's Kuiper belt, we deduce that Neptune likely underwent both planet-planet scattering and smooth migration caused by interactions with leftover planetesimals. In another planetary system, Beta Pictoris, we find that the giant planet discovered there must be responsible for the observed warp of the system's debris belt, reconciling observations that suggested otherwise. Second, we develop two new approaches for characterizing planetary orbits: one for distinguishing the signal of a planet's orbit from aliases, spurious signals caused by gaps in the time sampling of the data, and another to measure the eccentricity of a planet's orbit from transit photometry, "the photoeccentric effect." We use the photoeccentric effect to determine whether any of the giant planets discovered by the Kepler Mission are currently undergoing planetary migration on highly elliptical orbits. We find a lack of such "super-eccentric" Jupiters, allowing us to place an upper limit on the fraction of hot Jupiters created by the stellar binary Kozai mechanism. Finally, we find new correlations between the orbital properties of planets and the metallicity of their host stars. Planets orbiting metal-rich stars show signatures of strong planet-planet gravitational interactions, while those orbiting metal-poor stars do not. Taken together, the results of thesis suggest that suggest that both disk migration and planet-planet interactions likely play a role in setting the architectures of planetary systems. / Astronomy

The Kuiper belt is a population of small bodies located outside Neptune's orbit. The observed Kuiper belt objects (KBOs) can be divided into several subclasses based on their dynamical structure. I construct models for these subclasses and use numerical integrations to investigate their long-term evolution. I use these models to quantify the connection between the Kuiper belt and the Centaurs (objects whose orbits cross the orbits of the giant planets) and the short-period comets in the inner solar system. I discuss how these connections could be used to determine the physical properties of KBOs and what future observations could conclusively link the comets and Centaurs to specific Kuiper belt subclasses. The Kuiper belt's structure is determined by a combination of long-term evolution and its formation history. The large eccentricities and inclinations of some KBOs and the prevalence of KBOs in mean motion resonances with Neptune are evidence that much of the Kuiper belt's structure originated during the solar system's epoch of giant planet migration; planet migration can sculpt the Kuiper belt's scattered disk, capture objects into mean motion resonances, and dynamically excite KBOs. Different models for planet migration predict different formation locations for the subclasses of the Kuiper belt, which might result in different size distributions and compositions between the subclasses; the high-inclination portion of the classical Kuiper belt is hypothesized to have formed closer to the Sun than the low-inclination classical Kuiper belt. I use my model of the classical Kuiper belt to show that these two populations remain largely dynamically separate over long timescales, so primordial physical differences could be maintained until the present day.The current Kuiper belt is much less massive than the total mass required to form its largest members. It must have undergone a mass depletion event, which is likely related to planet migration. The Haumea collisional family dates from the end of this process. I apply long-term evolution to family formation models and determine how they can be observationally tested. Understanding the Haumea family's formation could shed light on the nature of the mass depletion event.

The Kuiper belt is a population of planetesimals outside the orbit of Neptune. The high inclinations and eccentricities exhibited by many belt members, and its very low mass (M 0.1M) present an enigma to planetesimal accretion scenarios: the high relative encounter velocities (vrei 1 km s-1), and infrequent collisions of the largest members make the growth of Pluto-sized bodies impossible over the age of the Solar system. Accretion in the early stages of planet-building must have been in a more dense environment allowing large objects to grow before growth was halted. The current Kuiper belt population is the left-over relic of accretion, which has undergone collisional re-shaping since the epoch of accretion. The shape of the size distribution can provide constraint on the accretion timescale, the primordial Kuiper belt mass, and the collisional processing the belt has undergone. Thus, a measure of the size distribution provides one of the primary constraint on models which attempt to explain the formation of the Kuiper belt. We have performed a large-scale ecliptic Kuiper belt survey, with an aerial cov¬erage of 3.3 square degrees to a limiting magnitude m(R) 27. From these ob¬servations, we have discovered more than 100 new Kuiper belt objects. Using this survey we have provided the best measurement of the Kuiper belt luminosity function to-date, from which we have inferred the size distribution. We have found that the size distribution is well described by a power-law for large objects with a steep slope q1 = 4.8, that breaks, or rolls over to a shallower power-law with slope q2 = 2 at ob¬ject diameter ~ 60 km. The steep large object slope is indicative of a short accretion phase, lasting no more than a few 100 Myr. The large break diameter demonstrates that the Kuiper belt has undergone substantial collisional processing. We have developed a collisional evolution model which we have used to study the effects of planetesimal bombardment and disruption on the size distribution. We have found that, in the current Kuiper belt, little to no evolution is occurring, or has occurred for the observable Kuiper belt. We conclude that the large break diameter cannot be produced in the current environment over the age of the Solar system. A period of intense collisional evolution in a much more dense, and hence, more massive belt is required. These findings are consistent with accretion models; the typical finding is that growth of the largest Kuiper belt objects over the age of the Solar system requires a much more massive belt than currently observed. These results point to a history in which an initially much more massive Kuiper belt underwent a short period of quiescent accretion producing Pluto size bodies. Some event then occurred, which dynamically excited the planetesimals, producing an erosive environment which effectively halted planet growth and rapidly depleted the majority of the primordial mass. The remnant of this depletion is the Kuiper belt we observe today.

Ultra-wide Trans-Neptunian Binaries (TNBs) are extremely sensitive to perturbation, and therefore make excellent probes of the past and present dynamical environment of the outer Solar System. Using data gathered from a host of facilities we have determined the mutual orbits for a sample of seven wide TNBs whose periods exceed one year. This characterized sample provides us with new information about the probable formation scenarios of TNBs, and has significant implications for the early dynamical and collisional history of the Kuiper Belt. We show that these wide binaries have short collisional lifetimes, and use them to produce a new estimate of the number of small (~1 km) objects in the Kuiper Belt. Additionally, these systems are susceptible to tidal disruption, and we show that it is unlikely that they were ever subjected to a period of close encounters with the giant planets. We find that the current properties of these ultra-wide Trans-Neptunian Binaries suggest that planetesimal growth in the Cold Classical Kuiper Belt did not occur through slow hierarchical accretion, but rather through rapid gravitational collapse. / Graduate

There are forty four known small planetary bodies with orbits that are contained within the heliocentric distances of Jupiter and Neptune. It is thought that the origin of these bodies is the Kuiper Belt, the predicted reservoir of the current short period comet population. Yet, only two bodies, Chiron and C/NEAT (2001 T4), have been shown to possess a visible coma. We've undertaken an observational survey of these bodies to obtain detailed characterization of the physical properties of the Centaurs to search for evidence of activity, and to use the physical characteristics to make inferences about primordial conditions in the outer solar nebula and evolutionary processes among different dynamical regimes in the outer nebula. We present the results of optical observations of 24 Centaurs, which yield a 3-σ correlation of color with semimajor axis, with redder Centaurs being farther from the Sun. The survey also revealed the rotation light curve period for 2 Centaurs, and the phase-darkening slope parameters, G, for 5 Centaurs which range from -0.18 to 0.13, agreeing with the steepest of main belt asteroid phase curve responses. We show spectral evidence of a variegated surface for 1999 UG5 and find the second reddest Centaur object is the active Centaur C/NEAT (2001 T4). We also present spectral evidence of crystalline water ice and ammonia species on our comparison object, the Uranian satellite Miranda.

abstract: Solar system orbital dynamics can offer unique challenges. Impacts of interplanetary dust particles can significantly alter the surfaces of icy satellites and minor planets. Impact heating from these particles can anneal away radiation damage to the crystalline structure of surface water ice. This effect is enhanced by gravitational focusing for giant planet satellites. In addition, impacts of interplanetary dust particles on the small satellites of the Pluto system can eject into the system significant amounts of secondary intra-satellite dust. This dust is primarily swept up by Pluto and Charon, and could explain the observed albedo features on Pluto's surface. In addition to Pluto, a large fraction of trans-neptunian objects (TNOs) are binary or multiple systems. The mutual orbits of these TNO binaries can range from very wide (periods of several years) to near-contact systems (less than a day period). No single formation mechanism can explain this distribution. However, if the systems generally formed wide, a combination of solar and body tides (commonly called Kozai Cycles-Tidal Friction, KCTF) can cause most systems to tighten sufficiently to explain the observed distributions. This KCTF process can also be used to describe the orbital evolution of a terrestrial-class exoplanet after being captured as a satellite of a habitable-zone giant exoplanet. The resulting exomoon would be both potentially habitable and potenially detectable in the full Kepler data set. / Dissertation/Thesis / Ph.D. Astrophysics 2013

Orientador: Ernesto Vieira Neto / Resumo: O estudo da formação e evolução do Sistema Solar é uma fonte de informação para entender sob quais condições a vida poderia surgir e evoluir. Nós apresentamos, nesta Tese de doutorado, um estudo numérico da fase final de acresção dos planetas gigantes do Sistema Solar durante e após a fase do disco de gás protoplanetário. Em nossas simulações, utilizamos um modelo recente e confiável para a formação de Urano e Netuno para esculpir as propriedades do disco trans-Netuniano original (Izidoro et al. , 2015a). Nós fizemos este estudo de uma maneira autoconsistente considerando os efeitos do gás e da evolução dos embriões planetários que formam Urano e Netuno por colisões gigantescas. Consideramos diferentes histórias de migração de Júpiter, devido a incerteza de como Júpiter migrou, durante a fase de gás. As nossas simulações permitiram obter pela primeira vez as propriedades orbitais do disco trans-Netuniano original. Então, calculamos o tempo de instabilidade dos planetas gigantes a partir de sistemas planetários que formam similares Urano e Netuno. Nossos resultados indicam fortemente que a instabilidade dos planetas gigantes acontecem cedo em até 500 milhões de anos e mais provável ainda ter acontecido em 136 milhões de anos após a dissipação do gás. Nós também realizamos simulações para discutir alguns efeitos dinâmicos que acontecem na região do cinturão de Kuiper. Estes efeitos acontecem quando Netuno esteve em alta excentricidade durante a instabilidade planetária. Para es... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: A study of the formation and evolution of the Solar System is a source of information for an understanding of what conditions life could arise and evolve. We present a numerical study of the final stage of accretion of the giant planets of the Solar System during and after the protoplanetary gas disc phase. In our simulations, we use a recent and reliable model for the formation of Uranus and Neptune to sculpt the properties of the original trans-Neptunian disk (Izidoro et al. , 2015a). We have done this study in a self-consistent way considering the effects of gas and the evolution of planetary embryos which form Uranus and Neptune by mutual giant collisions. We considered different Jupiter migration stories due to the uncertainty of how Jupiter’s migration was during the gas phase. Our simulations provide for the first time to obtain the orbital properties of the original trans-Neptunian disk. We then calculate the instability time of the giant planets from planetary systems which form similar Uranus and Neptune. Our results strongly indicate that the instability of the giant planets occurs early within 500 million years and even more likely to happen at 136 million years after gas dissipation. We also perform simulations to discuss some dynamical effects that happen in the Kuiper belt region. These effects happen when Neptune was in high eccentricity during planetary instability. For this problem, we use the simulations performed by Gomes et al. (2018) who investigated the... (Complete abstract click electronic access below) / Doutor

Les petits corps du système solaire riches en volatiles incluent plusieurs populations d’objets : les astéroïdes de la ceinture principale, les astéroïdes troyens des planètes géantes, les objets trans-neptuniens (OTNs) et les comètes. Au cours de ces dernières années, l'’idée que leur position actuelle résulte de migrations orbitales plutôt qu’elle ne reflète leur région de formation a progressivement émergée. Spécifiquement, certains astéroïdes pourraient être des comètes, et certaines comètes pourraient être des OTNs. Je présente ici les travaux réalisés au cours de ma thèse pour contraindre la composition (minéralogie de surface et structure interne) de ces différentes populations afin i) de déterminer les liens qui les unissent, ii) comprendre leurs migrations passées et donc, iii) apporter de nouvelles contraintes aux modèles dynamiques décrivant la formation et l’évolution de notre système solaire. À cet effet, j’ai principalement utilisé comme méthode d’analyse l’observation spectroscopique, ainsi que la modélisation des données obtenues et leur comparaison aux données spectrales de météorites et poussières cosmiques étudiées en laboratoire. / The icy small bodies of our solar system encompass several populations of objects : the main belt asteroids, the giant planets Trojans, the Trans-Neptunian Objects (TNOs) and the comets. During recent years, the idea that their present location is the result of orbital migrations rather than their true formation location has progressively emerged. Specifically, some asteroids could be comets, and some comets could be TNOs. Here, I present the studies carried out along my PhD aiming to constrain the physical properties of all these populations in order ultimately i) to determine the link between these populations, ii) bring key constraints to their past orbital evolution and thus iii) key constraints to the formation and evolution models for our Solar System. For that purpose, I have used spectroscopy as a main tool, as well as data modelling using a radiative transfert code and comparison of our astronomical data to laboratory measurements of meteorites and cosmic dust.