Planetary Imaging Concept Testbed Using a Recoverable Experiment-Coronagraph (PICTURE C)

An exoplanet mission based on a high-altitude balloon is a next logical step in humanity's quest to explore Earthlike planets in Earthlike orbits orbiting Sunlike stars. The mission described here is capable of spectrally imaging debris disks and exozodiacal light around a number of stars spanning a range of infrared excesses, stellar types, and ages. The mission is designed to characterize the background near those stars, to study the disks themselves, and to look for planets in those systems. The background light scattered and emitted from the disk is a key uncertainty in the mission design of any exoplanet direct imaging mission, thus, its characterization is critically important for future imaging of exoplanets

The 3D Acid Test: Perceptual Attributes vs Renderable Elements

The Romantics artificially embellished light and colour to convey emotion in their artworks. Light and colour were used to ignite a sense of enchantment and to stir an emotional response from the viewer. 3D software operates within this established visual tradition: current digital artistic representation involves a similarly embellished reality. This is a testament to what we continually want to see and how we would like to be visually entertained and informed, and physically based 3D renderer Arnold provides the tools for this continuation. Inherent in the world’s most-used 3D rendering programme Arnold are light and surface attributes which have been programmed to be adjustable to achieve myriad visual results. These attributes, however, have a history rooted in computer graphics’ plight for realism by abiding by the laws of optics and physics in their creation. However, these tools were designed with an arbitrarily chosen set of limits: arbitrary in the sense that these limits define a range of possibility to be used conveniently by the artist rather than by necessity or intrinsic nature. Johann Goethe (b. 1749), a Romantic poet, was critical of how light and colour were used by his artistic peers. He was dissatisfied by the embellishment of light and colour in paintings, and endeavoured to know exactly what was happening when he looked at things. Goethe conducted a series of experiments on light and colour, which resulted in his book Theory of Colours (1810, trans. Charles Eastlake, 1840). In my study, using Theory of Colours as a guideline, I have recreated fifty of Goethe’s experiments in 3D. I explore the fundamentals of Arnold as it was created, revealing the benchmark of current achievable 3D realism. Ten of these experiments are discussed in this paper. These experiments, in my judgment, are more applicable to the scope of phenomena replicable with a renderer, and scale the vast number of Goethe’s experiments in Theory of Colours to a reasonable set of testable conditions. The human perception of reality is the baseline against which rendering qualities must be judged, and Goethe’s experiments are replicable. As an instructor of 3D rendering, I aim to instill in my students the knowledge gained from this study, with the intention to empower the students with their own rendering so that they may make informed, predictable decisions

Stellar Systems at Low Radio Frequencies:The Discovery of Radio Exoplanets

For more than thirty years, radio astronomers have searched for auroral emission from exoplanets. With LOFAR we have recently detected strong, highly circularly polarised low-frequency (144 MHz) radio emission associated with a M-dwarf — the expected signpost of such radiation. The star itself is quiescent, with a 130-day rotation period and low X-ray luminosity. In this talk, I will detail how the radio properties of the detection imply that such emission is generated by the presence of an exoplanet in a short period orbit around the star, and our follow-up radial-velocity (RV) observations with Harps-N to confirm the exoplanet's presence. Our study highlights the powerful new and developing synergy between low-frequency radio astronomy and RV observations, with radio emission providing a strong prior on the presence of a short-period planet. I will conclude the talk detailing how the radio detection of an star-exoplanet interaction provides unique information for exoplanet climate and habitability studies, and the extension of our survey to other stellar systems

Learning geometric and lighting priors from natural images

Comprendre les images est d’une importance cruciale pour une pléthore de tâches, de la composition numérique au ré-éclairage d’une image, en passant par la reconstruction 3D d’objets. Ces tâches permettent aux artistes visuels de réaliser des chef-d’oeuvres ou d’aider des opérateurs à prendre des décisions de façon sécuritaire en fonction de stimulis visuels. Pour beaucoup de ces tâches, les modèles physiques et géométriques que la communauté scientifique a développés donnent lieu à des problèmes mal posés possédant plusieurs solutions, dont généralement une seule est raisonnable. Pour résoudre ces indéterminations, le raisonnement sur le contexte visuel et sémantique d’une scène est habituellement relayé à un artiste ou un expert qui emploie son expérience pour réaliser son travail. Ceci est dû au fait qu’il est généralement nécessaire de raisonner sur la scène de façon globale afin d’obtenir des résultats plausibles et appréciables. Serait-il possible de modéliser l’expérience à partir de données visuelles et d’automatiser en partie ou en totalité ces tâches ? Le sujet de cette thèse est celui-ci : la modélisation d’a priori par apprentissage automatique profond pour permettre la résolution de problèmes typiquement mal posés. Plus spécifiquement, nous couvrirons trois axes de recherche, soient : 1) la reconstruction de surface par photométrie, 2) l’estimation d’illumination extérieure à partir d’une seule image et 3) l’estimation de calibration de caméra à partir d’une seule image avec un contenu générique. Ces trois sujets seront abordés avec une perspective axée sur les données. Chacun de ces axes comporte des analyses de performance approfondies et, malgré la réputation d’opacité des algorithmes d’apprentissage machine profonds, nous proposons des études sur les indices visuels captés par nos méthodes.Understanding images is needed for a plethora of tasks, from compositing to image relighting, including 3D object reconstruction. These tasks allow artists to realize masterpieces or help operators to safely make decisions based on visual stimuli. For many of these tasks, the physical and geometric models that the scientific community has developed give rise to ill-posed problems with several solutions, only one of which is generally reasonable. To resolve these indeterminations, the reasoning about the visual and semantic context of a scene is usually relayed to an artist or an expert who uses his experience to carry out his work. This is because humans are able to reason globally on the scene in order to obtain plausible and appreciable results. Would it be possible to model this experience from visual data and partly or totally automate tasks? This is the topic of this thesis: modeling priors using deep machine learning to solve typically ill-posed problems. More specifically, we will cover three research axes: 1) surface reconstruction using photometric cues, 2) outdoor illumination estimation from a single image and 3) camera calibration estimation from a single image with generic content. These three topics will be addressed from a data-driven perspective. Each of these axes includes in-depth performance analyses and, despite the reputation of opacity of deep machine learning algorithms, we offer studies on the visual cues captured by our methods

The Divine Pedagogy: Theological Explorations of Intelligent Extraterrestrial Life

Abstract Speculation regarding the plurality of worlds and its closely related subject of the existence of intelligent extraterrestrials has remained an important question for Christian theology from antiquity until the modern age. Advancements in space science of the twentieth and twenty-first centuries have revealed a vast universe containing trillions of galaxies, as well as new discoveries of exoplanets, which has provided an unprecedented greater context and perspective in consideration of the place of humanity, possible intelligent extraterrestrials, and the role of divinity in relation to creatures. This has led to increased importance to the question regarding the relation of extraterrestrials to the Christian doctrines of the Incarnation and Redemption, which for centuries has evaded theological resolution. Historically, a handful of theologians have given limited attention to the question of the redemption of possible extraterrestrials, and since early Christianity have proposed several possible solutions, which are categorized according to four types: an exclusive view, asserting a single divine incarnation and salvation provided solely for humans on Earth, without access to potential extraterrestrials; an inclusive view, which includes extraterrestrials within the redemptive sacrifice of Christ on Earth; a multiple view, which posits multiple incarnations of the Logos in extraterrestrial civilizations for their redemption; and a varied view, which argues for the total freedom of divine plans in the salvation of intelligent extraterrestrials. This thesis will argue for the varied view in consideration of intelligent extraterrestrials, which allows for the ‘omni-properties’ of divinity in the creation and redemption of intelligent creatures according to divine prerogative. Examination of the history of developments in scientific and theological thought on extraterrestrials, from antiquity to the twenty-first century will demonstrate a consistent pattern of theological formulations of extraterrestrials and their relation to Christian Christology and Soteriology. In the discussion of this subject, an extraterrestrial ‘anthropology’, psychology, morphological possibilities, sociological compositions, extraterrestrial religions, implications of contact, and a ‘divine pedagogy’ of potential modalities of extra-mundus supernatural presence and action will be considered

On the hunt for Trappist-1 siblings

The TRAPPIST-South 60cm telescope at La Silla (ESO) is famously known for its detection of the extraordinary TRAPPIST-1 planetary system. A discovery made during the prototype phase of our ultra-cool dwarf transit survey SPECULOOS (Search for Planets EClipsing ULtra-cOOl Stars). This talk will first report on the self-consistence transit occurrence analysis of all observations of 42 bright ultra-cool dwarfs made with TRAPPIST-South during a period ranging from 2011 to 2017. On the basis that, with the exception of the discovery of TRAPPIST-1 planets, we didn't detect any other significant transiting event, we concluded on a 10% lower limit for the occurrence of planets similar to TRAPPIST-1b in this sample. The outcome is very sensitive to the size and period of the planet considered. A comprehensive statistic will be presented. Finally, performance obtained with our recently commissioned SPECULOOS Southern facility installed at Paranal will be presented. The lower occurrence limit measured with TRAPPIST survey will be compared with early results from 6 months of continue SPECULOOS core survey operations <P /

A Dynamical Synthesis of Planetary Systems

Over the past three decades, complementary lines of evidence have each provided tantalizing hints about the underlying mechanisms driving the diverse set of planetary system architectures. This dissertation leverages dynamics to synthesize the various components of planetary systems, including stars, planets, and minor planets. My work progresses at the intersection of subfields, drawing evidence from both solar system and exoplanet studies to advance a cohesive picture of planetary system evolution. This dissertation is fundamentally focused on interactions between the components of planetary systems. As a result, it is organized into three segments detailing the relationship between these components. A brief summary is provided as follows. Part I (Chapter 2): The Star-Minor Planet Connection. This chapter explores the use of occultation measurements, in which foreground asteroids briefly block out the light of background stars, as a mechanism to precisely probe the positions of minor planets within the solar system. We demonstrate that this method can be applied to constrain the presence of neighboring masses, including the predicted ``Planet Nine\u27\u27, in the distant solar system. Part II (Chapters 3-4): The Planet-Minor Planet Connection. These two chapters examine how minor planets can inform our understanding of planets more broadly. In Chapter 3, we describe a novel algorithm developed to directly search for distant solar system objects relevant to the Planet Nine hypothesis using data from the Transiting Exoplanet Survey Satellite (TESS). Then, in Chapter 4, we demonstrate that the long-period Neptune-mass exoplanet population suggested by protoplanetary disk images can also efficiently eject neighboring minor planets, accounting for the high rate of observed interstellar objects passing through the solar system. Part III (Chapters 5-7): The Star-Planet Connection. These three chapters investigate the relationship between stars and planets in two distinct ways: through compositional studies and through dynamical analyses. In Chapter 5, we describe the development of a machine learning algorithm that rapidly extracts stellar parameters, including 15 elemental abundances, from input optical stellar spectra. In Chapter 6, we introduce the Stellar Obliquities in Long-period Exoplanet Systems (SOLES) survey to investigate the origins of exoplanet spin-orbit misalignments. Finally, in Chapter 7 we conduct a population study of the stellar obliquity distribution that provides evidence for high-eccentricity migration and tidal damping as the two key mechanisms crafting the dynamical evolution of hot Jupiters