Extrasolar Planets Orbiting Active Stars

New discoveries of transiting extrasolar planets are reported weekly. Ground based surveys as well as space borne observatories like CoRoT and Kepler are responsible for filling the statistical voids of planets on distant stellar systems. I want to discuss the stellar activity and its impact on the discovery of extrasolar planets. Up to now the discovery of small rocky planets called "Super-Earths" like CoRoT-7b and Kepler-10b are the only exceptions. The question arises, why among over 500 detected and verified planets the amount of smaller planets is strikingly low. An explanation besides that the verification of small planets is an intriguing task, is the high level of stellar activity that has been observed. Stellar activity can be observed at different time-scales from long term irradiance variations similar to the well known solar cycle, over stellar rotation in the regime of days, down to the observations of acoustic modes in the domain of minutes. But also non periodic events like flares or the activity signal of the granulation can prevent the detection of a transiting Earth sized planet. I will describe methods to detect transit-like signals in stellar photometric data, the influences introduced by the star, the observer and their impact on the success. Finally different mathematical models and approximations of transit signals will be examined on their sensibility of stellar activity. I present a statistical overview of stellar activity in the CoRoT dataset. The influence of stellar activity will be analysed on different transiting planets: CoRoT-2b, CoRoT-4b und CoRoT-6b. Stellar activity can prevent the successful detection of a transiting planet, where CoRoT-7b marks the borderline. Future missions like Plato will be required to provide long-term observations with mmag precision to overcome the limitations set by active stars in our Galactic neighbourhood.Comment: PhD thesi

Stellar rotation, binarity, and lithium in the open cluster IC4756

An important aspect in the evolutionary scenario of cool stars is their rotation and the rotationally induced magnetic activity and interior mixing. Stars in open clusters are particularly useful tracers for these aspects because of their known ages. We aim to characterize the open cluster IC4756 and measure stellar rotation periods and surface differential rotation for a sample of its member stars. Thirty-seven cluster stars were observed continuously with the CoRoT satellite for 78 days in 2010. Follow-up high-resolution spectroscopy of the CoRoT targets and deep Str\"omgren $uvby\beta$ and H$\alpha$ photometry of the entire cluster were obtained with our robotic STELLA facility and its echelle spectrograph and wide-field imager, respectively. We determined high-precision photometric periods for 27 of the 37 CoRoT targets and found values between 0.155 and 11.4 days. Twenty of these are rotation periods. Twelve targets are spectroscopic binaries of which 11 were previously unknown; orbits are given for six of them. Six targets were found that show evidence of differential rotation with $\Delta\Omega/\Omega$ in the range 0.04-0.15. Five stars are non-radially pulsating stars with fundamental periods of below 1d, two stars are semi-contact binaries, and one target is a micro-flaring star that also shows rotational modulation. Nine stars in total were not considered members because of much redder color(s) and deviant radial velocities with respect to the cluster mean. H$\alpha$ photometry indicates that the cluster ensemble does not contain magnetically over-active stars. The cluster average metallicity is -0.08$\pm$0.06 (rms) and its logarithmic lithium abundance for 12 G-dwarf stars is 2.39$\pm$0.17 (rms). [...]Comment: A&A, in pres

TT Arietis - Observations of a Cataclysmic Variable Star with the MOST Space Telescope

We measured the photometric flux of the cataclysmic variable TT Arietis (BD+14 341) using the MOST space telescope. Periodic oscillations of the flux reveal the orbital period as well as other features of this binary system. We applied a Discrete Fourier Transform (DFT) on a reduced dataset to retrieve the frequencies of TT Arietis. The analysis of the system revealed a photometric period of 3.19 hours. Though the MOST data has a high cadence of 52.8 seconds, a fine structure of the accretion disk is not obvious.Comment: 3 pages, 1 figure, JENAM 2008 proceeding

Determinants of Paternity Success in a Group of Captive Vervet Monkeys ( Chlorocebus aethiops sabaeus )

Paternity success of high-ranking primate males is affected by the number of males and the number of fertile females and their cycle synchrony. Female vervets in the wild show strong reproductive seasonality and do not advertise the ovulatory period with conspicuous signals or behavior. Because this makes it difficult for males to monopolize fertile females, it can be expected that male reproductive skew in this species is lower than in other cercopithecines living in multimale groups that advertise the ovulatory period. We assessed male reproductive success in a captive vervet group, initially consisting of 4 males and 12 unrelated females. Besides a general low reproductive skew, we predicted paternity success of the alpha males to be dependent on the overlap of synchronously fertile females, month into alpha male tenure, and housing conditions (the subjects were kept in a large park but had to be locked in a small indoor compartment during the winter months). Further, because the number of males reaching their prime increased over time, we predicted a decrease in reproductive success of the alpha male with increasing tenure length of the alpha male. To assess this we collected genetic samples from 27 of 32 offspring born into the group during 3yr, using 7 polymorphic human microsatellite markers. Contrary to our predictions, reproductive success of the males occupying the alpha position during the study was among the highest found in cercopithecines, with the alpha males siring 78% of all offspring. The degree of overlapping fertile periods did not affect paternity success, nor did paternity success of the alpha male differ between the 2 housing conditions. Only the alpha male's tenure length had an effect. Alpha male reproductive success decreased over time, which we attribute to either a shift in female mate choice toward younger males or to increased competition among the males in the later stage of the alpha male's tenure. This study demonstrates the importance of assessing reproductive success of males throughout >1 season and should spawn more research into the role of female choice and postcopulatory mechanisms in this specie

Eficiência alfandegária e aeroportuária : atenuando o atraso na cadeia de abastecimento humanitária

Orientador : Claudia Mônica RitossaArtigo (especialização) - Universidade Federal do Paraná, Setor de Ciências Sociais Aplicadas, Curso de Especialização MBA em Gestão EstratégicaInclui referênciasResumo : Um aeroporto é a principal infraestrutura para mover ajuda após um desastre natural. Quando um desastre ocorre, e um pedido de assistência internacional é recebido, um número cada vez maior de atores responde às necessidades da população afetada. Há muitas partes interessadas envolvidas e isso pode empurrar a capacidade do aeroporto ao máximo e colocar muita pressão sobre a administração e funcionários aduaneiros. Infelizmente, poucas administrações aduaneiras estão adequadamente preparadas para a possibilidade de que, um dia, recebam uma grande quantidade de vôos entrantes em um curto período de tempo. Além disso, o excesso de regulação leva a estrangulamentos burocráticos desnecessários, que retardam a entrada e distribuição de alívio. Os provedores de ajuda são frustrados por atrasos desnecessários e custos mais elevados, enquanto as administrações aduaneiras não preparadas sofrem inúmeras dores de cabeça administrativas. Esta pesquisa centra-se nas causas de atraso no movimento de materiais que salvam vidas através da Alfândega e as barreiras associadas. O artigo inclui um desenho abrangente de análise qualitativa da literatura e entrevistas com informantes e é acompanhado de um modelo de Dinâmica do Sistema. Depois de revisar as ineficiências do sistema descobertas, recomendações para o caminho a seguir são feitas

Ensino médio e segregação urbana

The purpose of this paper is to discuss the influence of the place on schools, especially in high school, which marks the end of k-12 education and which, according to the official documents, should prepare students for life. Thus, considering the state high schools in the municipality of Suzano, in the metropolitan region of São Paulo, the paper will analyze the results of the School Performance Evaluation System of the State of São Paulo as well as the percentage of students graduating from grade 12 who took the National High School Examination to verify the influence that the place has on such variables. Finally, the reasons for this influence are discussed, pointing out the relation between urban segregation and low student achievement in impoverished neighborhoods.El objetivo de este trabajo es discutir la influencia del lugar sobre las escuelas, sobre todo en la enseñanza media, nivel que marca el fin de la educación básica y que, según los documentos oficiales, debería propiciar a los educandos inserción en la vida económica y social. En el caso de las escuelas estatales de nivel medio del municipio de Suzano, en la Grande São Paulo, se analizará los resultados del Sistema de Evaluación del Rendimiento Escolar del Estado de São Paulo y el porcentaje de alumnos concluyentes del tercer año medio que realizaron el programa Examen Nacional de Enseñanza Media para verificar la influencia que el lugar tiene sobre tales variables. Por último, se discute los motivos de tal influencia, apuntando la relación entre segregación urbana y bajo aprovechamiento de los alumnos en barrios periféricos.L’objet de cet article est de discuter de l’influence de la place sur les écoles, en particulier au lycée, qui marque la fin de l’éducation de base et qui, selon les documents officiels, devrait offrir aux étudiants une vie économique et sociale. Ainsi, en considérant les écoles publiques moyennes de la municipalité de Suzano, dans le Grand São Paulo, les résultats du système d’évaluation du rendement scolaire de l’État de São Paulo seront analysés et le pourcentage d’étudiants diplômés de la troisième année intermédiaire ayant terminé le Examen national des lycées pour vérifier l’influence de la place sur ces variables. Enfin, les raisons de cette influence sont discutées, en soulignant la relation entre la ségrégation urbaine et la faible réussite des élèves dans les quartiers périphériques.O objetivo desse trabalho é discutir a influência do lugar sobre as escolas urbanas, sobretudo no ensino médio, nível esse que marca o fim da educação básica e cujo objetivo é propiciar aos educandos inserção na vida econômica e social. Assim, se debruçando sobre as escolas estaduais de nível médio do município de Suzano, na Grande São Paulo, serão analisados os resultados do Sistema de Avaliação do Rendimento Escolar do Estado de São Paulo e a porcentagem de alunos concluintes do terceiro ano médio que realizaram o Exame Nacional de Ensino Médio para verificar a influência do lugar sobre tais variáveis. Por fim, serão discutidos os motivos de tal influência, apontando a relação entre segregação urbana e baixo aproveitamento dos alunos em bairros periféricos

Transmission spectroscopy of the inflated exo-Saturn HAT-P-19b

We observed the Saturn-mass and Jupiter-sized exoplanet HAT-P-19b to refine its transit parameters and ephemeris as well as to shed first light on its transmission spectrum. We monitored the host star over one year to quantify its flux variability and to correct the transmission spectrum for a slope caused by starspots. A transit of HAT-P-19b was observed spectroscopically with OSIRIS at the Gran Telescopio Canarias in January 2012. The spectra of the target and the comparison star covered the wavelength range from 5600 to 7600 AA. One high-precision differential light curve was created by integrating the entire spectral flux. This white-light curve was used to derive absolute transit parameters. Furthermore, a set of light curves over wavelength was formed by a flux integration in 41 wavelength channels of 50 AA width. We analyzed these spectral light curves for chromatic variations of transit depth. The transit fit of the combined white-light curve yields a refined value of the planet-to-star radius ratio of 0.1390 pm 0.0012 and an inclination of 88.89 pm 0.32 degrees. After a re-analysis of published data, we refine the orbital period to 4.0087844 pm 0.0000015 days. We obtain a flat transmission spectrum without significant additional absorption at any wavelength or any slope. However, our accuracy is not sufficient to significantly rule out the presence of a pressure-broadened sodium feature. Our photometric monitoring campaign allowed for an estimate of the stellar rotation period of 35.5 pm 2.5 days and an improved age estimate of 5.5^+1.8_-1.3 Gyr by gyrochronology.Comment: 14 pages, 9 figures, Accepted for publication in A&