Statistical Properties of Exoplanets
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Lurking in the Shadows: Wide-Separation Gas Giants As Tracers of Planet Formation
Lurking in the Shadows: Wide-Separation Gas Giants as Tracers of Planet Formation Thesis by Marta Levesque Bryan In Partial Fulfillment of the Requirements for the Degree of Doctor of Philosophy CALIFORNIA INSTITUTE OF TECHNOLOGY Pasadena, California 2018 Defended May 1, 2018 ii © 2018 Marta Levesque Bryan ORCID: [0000-0002-6076-5967] All rights reserved iii ACKNOWLEDGEMENTS First and foremost I would like to thank Heather Knutson, who I had the great privilege of working with as my thesis advisor. Her encouragement, guidance, and perspective helped me navigate many a challenging problem, and my conversations with her were a consistent source of positivity and learning throughout my time at Caltech. I leave graduate school a better scientist and person for having her as a role model. Heather fostered a wonderfully positive and supportive environment for her students, giving us the space to explore and grow - I could not have asked for a better advisor or research experience. I would also like to thank Konstantin Batygin for enthusiastic and illuminating discussions that always left me more excited to explore the result at hand. Thank you as well to Dimitri Mawet for providing both expertise and contagious optimism for some of my latest direct imaging endeavors. Thank you to the rest of my thesis committee, namely Geoff Blake, Evan Kirby, and Chuck Steidel for their support, helpful conversations, and insightful questions. I am grateful to have had the opportunity to collaborate with Brendan Bowler. His talk at Caltech my second year of graduate school introduced me to an unexpected population of massive wide-separation planetary-mass companions, and lead to a long-running collaboration from which several of my thesis projects were born. -
Astronomy DOI: 10.1051/0004-6361/201423537 & C ESO 2014 Astrophysics
A&A 565, A124 (2014) Astronomy DOI: 10.1051/0004-6361/201423537 & c ESO 2014 Astrophysics Carbon monoxide and water vapor in the atmosphere of the non-transiting exoplanet HD 179949 b? M. Brogi1, R. J. de Kok1;2, J. L. Birkby1, H. Schwarz1, and I. A. G. Snellen1 1 Leiden Observatory, Leiden University, PO Box 9513, 2300 RA Leiden, The Netherlands e-mail: [email protected] 2 SRON Netherlands Institute for Space Research, Sorbonnelaan 2, 3584 CA Utrecht, The Netherlands Received 29 January 2014 / Accepted 5 April 2014 ABSTRACT Context. In recent years, ground-based high-resolution spectroscopy has become a powerful tool for investigating exoplanet atmo- spheres. It allows the robust identification of molecular species, and it can be applied to both transiting and non-transiting planets. Radial-velocity measurements of the star HD 179949 indicate the presence of a giant planet companion in a close-in orbit. The system is bright enough to be an ideal target for near-infrared, high-resolution spectroscopy. Aims. Here we present the analysis of spectra of the system at 2.3 µm, obtained at a resolution of R ∼ 100 000, during three nights of observations with CRIRES at the VLT. We targeted the system while the exoplanet was near superior conjunction, aiming to detect the planet’s thermal spectrum and the radial component of its orbital velocity. Methods. Unlike the telluric signal, the planet signal is subject to a changing Doppler shift during the observations. This is due to the changing radial component of the planet orbital velocity, which is on the order of 100–150 km s−1 for these hot Jupiters. -
“Spectra and Photometry: Windows Into Exoplanet Atmospheres”
“Spectra and Photometry: Windows into Exoplanet Atmospheres” A. Burrows Dept. of Astrophysical Sciences Princeton University Transiting Planets Secondary Eclipse See thermal radiation and reflected light from planet disappear and reappear Transit Orbital Phase Variations See stellar flux decrease See cyclical variations in (function of wavelength) brightness of planet figure taken from H. Knutson! With upper- atmosphere optical absorber! Transit chord Graphics by D. Spiegel! Haze on HD 189733b Figure from Pont, Knutson et al. (2007) showing atmospheric transmission function derived from HST ACS measurements between 600-1000 nm Pont et al .2013: Haze on HD 189733b Pont et al. 2013 GJ 1214b: Transit Radius vs. Wavelength! Howe & Burrows 2012, in press HST GJ1214b transit spectrum – Kreidberg et al. 2014 Hazes! Figure 2: The transmission spectrum of GJ1214b. a,Transmissionspectrummeasurements from our data (black points) and previous work (gray points)7–11,comparedtotheoreticalmodels (lines). The error bars correspond to 1 σ uncertainties. Each data set is plotted relative to its mean. Our measurements are consistent with past results for GJ1214usingWFC310.Previousdatarule out a cloud-free solar composition (orange line), but are consistent with a high-mean molecular weight atmosphere (e.g. 100% water, blue line) or a hydrogen-rich atmosphere with high-altitude clouds. b,Detailviewofourmeasuredtransmissionspectrum(blackpoints) compared to high mean molecular weight models (lines). The error bars are 1 σ uncertainties in the posterior distri- bution from a Markov chain Monte Carlo fit to the light curves (see the Supplemental Information for details of the fits). The colored points correspond to the models binned at the resolution of the observations. -
Appendix 1 Some Astrophysical Reminders
Appendix 1 Some Astrophysical Reminders Marc Ollivier 1.1 A Physics and Astrophysics Overview 1.1.1 Star or Planet? Roughly speaking, we can say that the physics of stars and planets is mainly governed by their mass and thus by two effects: 1. Gravitation that tends to compress the object, thus releasing gravitational energy 2. Nuclear processes that start as the core temperature of the object increases The mass is thus a good parameter for classifying the different astrophysical objects, the adapted mass unit being the solar mass (written Ma). As the mass decreases, three categories of objects can be distinguished: ∼ 1. if M>0.08 Ma ( 80MJ where MJ is the Jupiter mass) the mass is sufficient and, as a consequence, the gravitational contraction in the core of the object is strong enough to start hydrogen fusion reactions. The object is then called a “star” and its radius is proportional to its mass. 2. If 0.013 Ma <M<0.08 Ma (13 MJ <M<80 MJ), the core temperature is not high enough for hydrogen fusion reactions, but does allow deuterium fu- sion reactions. The object is called a “brown dwarf” and its radius is inversely proportional to the cube root of its mass. 3. If M<0.013 Ma (M<13 MJ) the temperature a the center of the object does not permit any nuclear fusion reactions. The object is called a “planet”. In this category one distinguishes giant gaseous and telluric planets. This latter is not massive enough to accrete gas. The mass limit between giant and telluric planets is about 10 terrestrial masses. -
Maio - 2017 Francisco Jânio Cavalcante
UNIVERSIDADE FEDERAL DO RIO GRANDE DO NORTE CENTRO DE CIÊNCIAS EXATAS E DA TERRA DEPARTAMENTO DE FÍSICA TEÓRICA E EXPERIMENTAL PROGRAMA DE PÓS-GRADUAÇÃO EM FÍSICA EVOLUÇÃO DO ÍNDICE DE FREIO MAGNÉTICO PARA ESTRELAS DO TIPO SOLAR FRANCISCO JÂNIO CAVALCANTE NATAL (RN) MAIO - 2017 FRANCISCO JÂNIO CAVALCANTE EVOLUÇÃO DO ÍNDICE DE FREIO MAGNÉTICO PARA ESTRELAS DO TIPO SOLAR Tese de Doutorado apresentada ao Programa de Pós-Graduação em Física do Departamento de Física Teórica e Experimental da Universidade Federal do Rio Grande do Norte como requisito parcial para a obtenção do grau de Doutor em Física. Orientador: Dr. Daniel Brito de Freitas NATAL (RN) MAIO - 2017 UFRN / Biblioteca Central Zila Mamede Catalogação da Publicação na Fonte Cavalcante, Francisco Jânio. Evolução do índice de freio magnético para estrelas do tipo solar / Francisco Jânio Cavalcante. - 2017. 166 f. : il. Tese (doutorado) - Universidade Federal do Rio Grande do Norte, Centro de Ciências Exatas e da Terra, Programa de Pós-Graduação em Física. Natal, RN, 2017. Orientador: Prof. Dr. Daniel Brito de Freitas. 1. Rotação estelar - Tese. 2. Freio magnético - Tese. 3. Distribuição e estatística - Tese. I. Freitas, Daniel Brito de. II. Título. RN/UF/BCZM CDU 524.3 Para Pessoas Especiais: A minha avó, minha mãe e minha namorada Ester Saraiva da Silva (in memorian) Cleta Carneiro Cavalcante Simone Santos Martins Agradecimentos Agradeço ao bom e generoso Deus, quem me deu muitas coisas no decorrer da minha vida. Deu-me compreensão e amparo nos momento de aflição e tristeza, saúde para continuar nesta caminhada. Ofereceu-me sua luz no momento em que a escuridão sufocava meu espírito. -