The Lick-Carnegie Survey: A New Two-Planet System Around the Star HD 207832

Keck/HIRES precision radial velocities of HD 207832 indicate the presence of two Jovian-type planetary companions in Keplerian orbits around this G star. The planets have minimum masses of 0.56 and 0.73 Jupiter-masses with orbital periods of ~162 and ~1156 days, and eccentricities of 0.13 and 0.27, respectively. Stromgren b and y photometry reveals a clear stellar rotation signature of the host star with a period of 17.8 days, well separated from the period of the radial velocity variations, reinforcing their Keplerian origin. The values of the semimajor axes of the planets suggest that these objects have migrated from the region of giant planet formation to closer orbits. In order to examine the possibility of the existence of additional (small) planets in the system, we studied the orbital stability of hypothetical terrestrial-sized objects in the region between the two planets and interior to the orbit of the inner body. Results indicated that stable orbits exist only in a small region interior to planet b. However, the current observational data offer no evidence for the existence of additional objects in this system.Comment: 23 pages, 4 figures, 5 tables, accepted for publication in Ap

Up to four planets around the M dwarf GJ 163 : Sensitivity of Bayesian planet detection criteria to prior choice

M. Tuomi and G. Anglada-Escude, 'Up to four planes around the M dwarf GJ 163: Sensitivity of Bayesian planet detection criteria to prior choice', Astronomy & Astrophysics, Vol. 556, A111 (2013), available online at DOI: 10.1051/0004-6361/201321174 © ESO 2013 Published by EDP SciencesContext. Exoplanet Doppler surveys are currently the most efficient means to detect low-mass companions to nearby stars. Among these stars, the light M dwarfs provide the highest sensitivity to detect low-mass exoplanet candidates. Evidence is accumulating that a substantial fraction of these low-mass planets are found in high-multiplicity planetary systems. GJ 163 is a nearby inactive M dwarf with abundant public observations obtained using the HARPS spectrograph. Aims. We obtain and analyse radial velocities from the HARPS public spectra of GJ 163 and investigate the presence of a planetary companions orbiting it. The number of planet candidates detected might depend on some prior assumptions. Since the impact of prior choice has not been investigated throughly previously, we study the effects of different prior densities on the detectability of planet candidates around GJ 163. Methods. We use Bayesian tools, i.e. posterior samplings and model comparisons, when analysing the GJ 163 velocities. We consider models accounting for the possible correlations of subsequent measurements. We also search for activity-related counterparts of the signals we observe and test the dynamical stability of the planetary systems corresponding to our solutions using direct numerical integrations of the orbits. Results. We find that there are at least three planet candidates orbiting GJ 163. The existence of a fourth planet is supported by the data but the evidence in favor of the corresponding model is not yet conclusive. The second innermost planet candidate in the system with an orbital period of 25.6 days and a minimum mass of 8.7 M· is inside the liquid-water habitable zone of the star. Conclusions. The architecture of GJ 163 system resembles a scaled-down Solar System in the sense that there are two low-mass planets on orbital periods of 8.7 and 25.6 days in the inner system, a possible slightly more massive companion on an intermediate orbit, and an outer sub-Saturnian companion at roughly 1 AU. The discovery of (yet) another planetary system with several low-mass companions around a nearby M-dwarf indicates that the high-multiplicity planetary systems found by the NASA Kepler mission around G and K dwarfs is also present (possibly even reinforced) around low-mass stars. © 2013 ESO.Peer reviewe

Educação física em ação: a eficácia da utilização de um vlog como recurso didático no ensino médio integrado

O objetivo deste estudo foi desenvolver um recurso didático capaz de aumentar o interesse pelas aulas de Educação Física em um curso técnico do Ensino Médio Integrado no Instituto Federal do Amazonas (IFAM) campus Presidente Figueiredo. A pesquisa é de natureza aplicada, com abordagem qualitativa e método de pesquisa-ação, com utilização de pesquisa bibliográfica, documental e o questionário como técnicas de coleta de dados. Participaram do estudo 65 alunos. A primeira etapa envolveu a seleção dos conteúdos, criação dos roteiros e gravação de videoaulas. Na segunda etapa ocorreu a aplicação das videoaulas por meio de um Vlog. A terceira etapa foi composta pela avaliação do Vlog. Os resultados apontaram uma melhora significativa na aprendizagem e também o aumento da participação e interesse dos alunos pelas aulas de Educação Física

Projeto Integrador: articulação para o ensino da pesquisa científica na formação técnica de nível médio

Middle-level technical training policies establish that the student's training process must privilege the development of scientific investigation competence which can be developed through teaching, research and extension. The study aimed to verify how the Integrative Project is structured to articulate the teaching of the scientific research methodology in middle-level technical professional education courses at the Federal Institute of Education, Science and Technology of Amazonas, Manaus Campus-Downtown. The methodological basis used was the bibliographic and documentary research. The result of the study outlines that the Integrative Project established as a curricular component can be combined with another specific component or worked out individually in the context of Complementary Activities to articulate the teaching of the scientific research methodology in middle-level technical professional education courses at the Federal Institute of Education, Science and Technology of Amazonas. Keywords: Integrative Project; Scientific research methodology; Teaching; Middle-Level Technical Professional Education.As políticas da formação técnica de nível médio estabelecem que o processo de formação do aluno deve privilegiar o desenvolvimento da capacidade de investigação científica que pode ser desenvolvida por meio do ensino, pesquisa e extensão. O estudo objetivou verificar como está estruturado o Projeto Integrador para articular o ensino da metodologia da pesquisa científica nos cursos da educação profissional técnica de nível médio no Campus Manaus Centro do IFAM. Teve base metodológica na pesquisa bibliográfica e documental. O resultado do estudo esboça que o Projeto Integrador estabelecido como componente curricular pode ser combinado com outro componente específico ou trabalhado individualmente no contexto das Atividades Complementares para articular o ensino da metodologia da pesquisa científica nos cursos da educação profissional técnica de nível médio do IFAM. Palavras-chave: Projeto Integrador; Metodologia da pesquisa científica; Ensino; Educação Profissional Técnica de Nível Médio

O Pensamento Computacional como Objeto de Estudo na Formação Inicial de Professores em Pesquisas de Doutorado: uma Revisão Sistemática

This work presents a Systematic Literature Review - RSL, which aimed to carry out a mapping to investigate how Computational Thinking has been approached in initial teacher training courses, in doctoral research in Brazil. For this, protocols were defined based on Kietchenham's methodological proposal, with the period between 2006 and 2021 as the search period. Based on the results found, it was possible to verify that there is still little research being developed specifically in the initial training of teachers. Of a total of 36 theses containing computational thinking as a theme, only 3 of them report experiences in the initial training of teachers in undergraduate courses in mathematics and pedagogy.Este trabalho apresenta uma Revisão Sistemática da Literatura – RSL, que teve como objetivo realizar um mapeamento para investigar de que maneira o Pensamento Computacional tem sido abordado em cursos de formação inicial de professores, em pesquisas de doutorado no Brasil. Para isso, foram definidos protocolos com base na proposta metodológica de Kietchenham, tendo como período de busca os anos entre 2006 e 2021. Com base nos resultados encontrados, foi possível verificar que ainda existem poucas pesquisas sendo desenvolvidas especificamente na formação inicial de professores. De um total de 36 teses contendo o pensamento computacional como tema, apenas 3 delas relatam experiências na formação inicial de professores em cursos licenciatura em matemática e pedagogia

Two super-earths orbiting the solar analog HD 41248 on the edge of a 7 : 5 mean motion resonance

J. S. Jenkins, M. Tuomi, R. Brasser, O. Ivanyuk, and F. Murgas, 'Two super-Earths orbiting the solar analog HD 41248 on the edge of a 7:5 mean motion resonance', The Astrophysical Journal, Vol. 771:41 (13 pp), first published online 14 June 2013. The version of record is available online at doi: 10.1088/0004-637X/771/1/41 © 2013. The American Astronomical Society. All rights reserved.There are a growing number of multi-planet systems known to be orbiting their host stars with orbital periods that place them in mean motion resonances (MMRs). These systems are generally in first-order resonances and dynamical studies have focused their efforts on understanding the origin and evolution of such dynamically resonant commensurabilities. Here we report the discovery of two super-Earths that are close to a second-order dynamical resonance orbiting the metal-poor ([Fe/H] = -0.43 dex) and inactive G2V star HD 41428. We analyzed 62 HARPS archival radial velocities for this star that, until now, exhibited no evidence for planetary companions. Using our new Bayesian Doppler signal detection algorithm, we find two significant signals in the data, with periods of 18.357 days and 25.648 days, indicating they could be part of a 7:5 second-order MMR. Both semi-amplitudes are below 3 m s-1 and the minimum masses of the pair are 12.3 and 8.6 M⊕, respectively. Our simulations found that apsidal alignment stabilizes the system, and even though libration of the resonant angles was not seen, the system is affected by the presence of the resonance and could still occupy the 7:5 commensurability, which would be the first planetary configuration in such a dynamical resonance. Given the multitude of low-mass multi-planet systems that will be discovered in the coming years, we expect that more of these second-order resonant configurations will emerge from the data, highlighting the need for a better understanding of the dynamical interactions between forming planetesimals.Peer reviewe

Radial velocity planets de-aliased. A new, short period for Super-Earth 55 Cnc e

Radial velocity measurements of stellar reflex motion have revealed many extrasolar planets, but gaps in the observations produce aliases, spurious frequencies that are frequently confused with the planets' orbital frequencies. In the case of Gl 581 d, the distinction between an alias and the true frequency was the distinction between a frozen, dead planet and a planet possibly hospitable to life (Udry et al. 2007; Mayor et al. 2009). To improve the characterization of planetary systems, we describe how aliases originate and present a new approach for distinguishing between orbital frequencies and their aliases. Our approach harnesses features in the spectral window function to compare the amplitude and phase of predicted aliases with peaks present in the data. We apply it to confirm prior alias distinctions for the planets GJ 876 d and HD 75898 b. We find that the true periods of Gl 581 d and HD 73526 b/c remain ambiguous. We revise the periods of HD 156668 b and 55 Cnc e, which were afflicted by daily aliases. For HD 156668 b, the correct period is 1.2699 days and minimum mass is (3.1 +/- 0.4) Earth masses. For 55 Cnc e, the correct period is 0.7365 days -- the shortest of any known planet -- and minimum mass is (8.3 +/- 0.3) Earth masses. This revision produces a significantly improved 5-planet Keplerian fit for 55 Cnc, and a self-consistent dynamical fit describes the data just as well. As radial velocity techniques push to ever-smaller planets, often found in systems of multiple planets, distinguishing true periods from aliases will become increasingly important.Comment: Accepted by ApJ (in press); 19 pages, 22 figures. Fixed typos; improved wording; added more extensive discussion of orbital eccentricity; improved figure captions; additional reference

Astrometry and radial velocities of the planet host M dwarf GJ 317: new trigonometric distance, metallicity and upper limit to the mass of GJ 317b

We have obtained precision astrometry of the planet hosting M dwarf GJ 317 in the framework of the Carnegie Astrometric Planet Search project. The new astrometric measurements give a distance determination of 15.3 pc, 65% further than previous estimates. The resulting absolute magnitudes suggest it is metal rich and more massive than previously assumed. This result strengthens the correlation between high metallicity and the presence of gas giants around low mass stars. At 15.3 pc, the minimal astrometric amplitude for planet candidate GJ 317b is 0.3 milliarcseconds (edge-on orbit), just below our astrometric sensitivity. However, given the relatively large number of observations and good astrometric precision, a Bayesian Monte Carlo Markov Chain analysis indicates that the mass of planet b has to be smaller than twice the minimum mass with a 99% confidence level, with a most likely value of 2.5 Mjup. Additional RV measurements obtained with Keck by the Lick-Carnegie Planet search program confirm the presence of an additional very long period planet candidate, with a period of 20 years or more. Even though such an object will imprint a large astrometric wobble on the star, its curvature is yet not evident in the astrometry. Given high metallicity, and the trend indicating that multiple systems are rich in low mass companions, this system is likely to host additional low mass planets in its habitable zone that can be readily detected with state-of-the-art optical and near infrared RV measurements.Comment: 20 pages of text, 9 Figures, 8 tables. Accepted in ApJ (in press

Bayesian search for low-mass planets around nearby M dwarfs. Estimates for occurrence rate based on global detectability statistics

Mikko Tuomi, 'Bayesian search for low-mass planets around nearby M dwarfs - estimates for occurrence rate based on global detectability statistics', Monthly Notices of the Royal Astronomical Society, Vol. 441 (2): 1545-1569, first published online 8 May 2014. The version of record is available online at doi: 10.1093/mnras/stu358 © 2014 The Authors. Published by Oxford University Press on behalf of the Royal Astronomical Society.Due to their higher planet-star mass ratios, M dwarfs are the easiest targets for detection of low-mass planets orbiting nearby stars using Doppler spectroscopy. Furthermore, because of their low masses and luminosities, Doppler measurements enable the detection of lowmass planets in their habitable zones that correspond to closer orbits than for solar-type stars. We re-analyse literature Ultraviolet and Visual Echelle Spectrograph (UVES) radial velocities of 41 nearby Mdwarfs in a combination with new velocities obtained from publicly available spectra from the HARPS-ESO spectrograph of these stars in an attempt to constrain any low-amplitude Keplerian signals. We apply Bayesian signal detection criteria, together with posterior sampling techniques, in combination with noise models that take into account correlations in the data and obtain estimates for the number of planet candidates in the sample. More generally, we use the estimated detection probability function to calculate the occurrence rate of low-mass planets around nearby M dwarfs. We report eight new planet candidates in the sample (orbiting GJ 27.1, GJ 160.2, GJ 180, GJ 229, GJ 422, and GJ 682), including two new multiplanet systems, and confirm two previously known candidates in the GJ 433 system based on detections of Keplerian signals in the combined UVES and High Accuracy Radial velocity Planet Searcher (HARPS) radial velocity data that cannot be explained by periodic and/or quasi-periodic phenomena related to stellar activities. Finally, we use the estimated detection probability function to calculate the occurrence rate of low-mass planets around nearby M dwarfs. According to our results, M dwarfs are hosts to an abundance of low-mass planets and the occurrence rate of planets less massive than 10M? is of the order of one planet per star, possibly even greater. Our results also indicate that planets with masses between 3 and 10 M⊕ are common in the stellar habitable zones of M dwarfs with an estimated occurrence rate of 0.21+0.03 -0.05 planets per star.Peer reviewe

Treating dynamical stability as an observable: a 5:2 MMR configuration for the extrasolar system HD 181433

The three-planet extrasolar system of HD 181433 has been detected with HARPS. The best-fit solution, announced by the discovery team, describes a highly unstable, self-disrupting configuration. In fact, a narrow observational window, only partially covering the longest orbital period, can lead to solutions representing unrealistic scenarios. Taking into account the dynamical stability as an additional observable while interpreting the RV data, we can analyse the phase space in a neighbourhood of the statistically best-fit and derive dynamically stable configurations that reproduce the observed RV signal. Our Newtonian stable best-fit model is capable of surviving for at least 250 Myrs. The two giant companions are found to be locked in the 5:2 MMR as Jupiter and Saturn in the Solar System. This mechanism does not allow close encounters even in case of highly eccentric orbits. Moreover, planets c and d are located in regions spanned by many other strong low-order MMRs. We study the dynamics of some plausible scenarios and we illustrate the behaviours caused by secular apsidal resonances and mean motion resonances. Furthermore, we find a terrestrial planet in the habitable zone of HD 181433 can retain stability. Apart from filling an empty gap in the system, this body could offer a harbour for life indeed. Additional measurements are necessary in order to investigate this hypothesis and can confirm the predictions outlined in the paper.Comment: The paper contains 13 figures and 1 table. Accepted for publication in Monthly Notices of the Royal Astronomical Society Main Journa