Modelo Bayesiano de dados espaciais aplicado ao mapeamento da integridade ecossistêmica da Amazônia brasileira.

A relação entre a perda de biodiversidade e os impactos nos serviços ecossistêmicos de florestas tropicais, em face à mudança global do clima em curso precisa ser melhor quantificada. Neste trabalho, considerou-se o conceito de Integridade Ecossistêmica (IE), que representa a conexão da biodiversidade com a capacidade dos ecossistemas em manterem os processos de auto-organização. As redes bayesianas (BBN- Bayesian Belief Network) podem fornecer métricas para a geração do índice de integridade do ecossistema, a partir do treinamento das relações probabilísticas de evidências obtidas através de dados de campo, dados de Sensoriamento Remoto e GIS. Assim, o objetivo deste trabalho é apresentar a abordagem metodológica e os resultados preliminares do mapeamento da IE, elaborada em escala regional para diferentes padrões fitoecológicos de paisagem da Amazônia brasileira. A modelagem baseou-se na aprendizagem dos parâmetros (modelo data-driven) através do algoritmo Expectation Maximization. Para a validação deste modelo probabilístico foi realizada uma avaliação em zonas controladas, observação de campo e comparação com o modelo de IE baseado em conhecimento (knowledge driven), elaborado por especialistas

Assessing the current state and restoration needs of the beaches and coastal dunes of Marismas Nacionales, Nayarit, Mexico

Around the world, population growth, land use changes and coastal infrastructure have modified coastlines. In many cases these actions have induced intense degradation and loss of the ecosystems there. Sandy beaches and coastal dunes are amongst the most threatened features. In Mexico, coastal dunes in the state of Nayarit, on the Pacific, have been affected by small scale tourism, the construction of artificial inlets and an increase in agricultural activities, even though they are part of a Biosphere Reserve. While there is a growing need for restoration or rehabilitation programs to protect these coastal dunes, such actions are almost non-existent because of financial limitations, difficulties in deciding which locations most urgently need these strategies, and the uncertainty of the results. Our goal was to evaluate the coastline of the Marismas Nacionales Biosphere Reserve, in the state of Nayarit, Mexico, examining geomorphological, ecological, and socioeconomic variables. Ninety sites were assessed, using the Re-Dune index, 41 beaches were found to be in a good state of conservation, while 43 are degraded but with the potential for success when subjected to restoration measures. Six sites were seen as highly degraded, with rehabilitation being the most viable option. By recovering the coastal dunes of Marismas Nacionales, the hurricane protection provided by them will be enhanced and sustainable social and economic development will be more likely.CEMIE-Océano 24979

A transiting companion to the eclipsing binary KIC002856960

We present an early result from an automated search of Kepler eclipsing binary systems for circumbinary companions. An intriguing tertiary signal has been discovered in the short period eclipsing binary KIC002856960. This third body leads to transit-like features in the light curve occurring every 204.2 days, while the two other components of the system display eclipses on a 6.2 hour period. The variations due to the tertiary body last for a duration of \sim1.26 days, or 4.9 binary orbital periods. During each crossing of the binary orbit with the tertiary body, multiple individual transits are observed as the close binary stars repeatedly move in and out of alignment with the tertiary object. We are at this stage unable to distinguish between a planetary companion to a close eclipsing binary, or a hierarchical triply eclipsing system of three stars. Both possibilities are explored, and the light curves presented.Comment: Accepted into A&A Letters (5 pages & 3 figures

The EBLM project. II. A very hot, low-mass M dwarf in an eccentric and long period eclipsing binary system from SuperWASP

In this paper, we derive the fundamental properties of 1SWASPJ011351.29+314909.7 (J0113+31), a metal-poor (-0.40 +/- 0.04 dex), eclipsing binary in an eccentric orbit (~0.3) with an orbital period of ~14.277 d. Eclipsing M dwarfs orbiting solar-type stars (EBLMs), like J0113+31, have been identified from WASP light curves and follow-up spectroscopy in the course of the transiting planet search. We present the first binary of the EBLM sample to be fully analysed, and thus, define here the methodology. The primary component with a mass of 0.945 +/- 0.045 Msun has a large radius (1.378 +/- 0.058 Rsun) indicating that the system is quite old, ~9.5 Gyr. The M-dwarf secondary mass of 0.186 +/- 0.010 Msun and radius of 0.209 +/- 0.011 Rsun are fully consistent with stellar evolutionary models. However, from the near-infrared secondary eclipse light curve, the M dwarf is found to have an effective temperature of 3922 +/- 42 K, which is ~600 K hotter than predicted by theoretical models. We discuss different scenarios to explain this temperature discrepancy. The case of J0113+31 for which we can measure mass, radius, temperature and metallicity, highlights the importance of deriving mass, radius and temperature as a function of metallicity for M dwarfs to better understand the lowest mass stars. The EBLM Project will define the relationship between mass, radius, temperature and metallicity for M dwarfs providing important empirical constraints at the bottom of the main sequence.Comment: 13 pages, 7 figures. Accepted for publication in A&

Discarding orbital decay in WASP-19b after one decade of transit observations

We present an empirical study of orbital decay for the exoplanet WASP-19b, based on mid-time measurements of 74 complete transits (12 newly obtained by our team and 62 from the literature), covering a 10-yr baseline. A linear ephemeris best represents the mid-transit times as a function of epoch. Thus, we detect no evidence of the shortening of WASP-19b's orbital period and establish an upper limit of its steady changing rate, P' = −2.294 ms yr−1, and a lower limit for the modified tidal quality factor Q'* = (1.23 ± 0.231) × 106. Both are in agreement with previous works. This is the first estimation of Q' directly derived from the mid-times of WASP-19b obtained through homogeneously analysed transit measurements. Additionally, we do not detect periodic variations in the transit timings within the measured uncertainties in the mid-times of transit. We are therefore able to discard the existence of planetary companions in the system down to a few M in the first-order mean-motion resonances 1:2 and 2:1 with WASP-19b, in the most conservative case of circular orbits. Finally, we measure the empirical Q'* values of 15 exoplanet host stars, which suggest that stars with Teff ≲ 5600 K dissipate tidal energy more efficiently than hotter stars. This tentative trend needs to be confirmed with a larger sample of empirically measured Q'*.Fil: Petrucci, Romina Paola. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de Córdoba. Observatorio Astronómico de Córdoba. Departamento de Astrofísica Estelar; ArgentinaFil: Jofre, Jorge Emiliano. Universidad Nacional de Córdoba. Observatorio Astronómico de Córdoba. Departamento de Astrofísica Estelar; Argentina. Universidad Nacional Autónoma de México; México. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Gómez Maqueo Chew, Y.. Universidad Nacional Autónoma de México; MéxicoFil: Hinse, T. C.. Chungnam National University; Corea del SurFil: Mazek, M.. Institute Of Physics Czech Academy Of Sciences; República ChecaFil: Tan, T. -G.. Perth Exoplanet Survey Telescope; AustraliaFil: Gomez, Mercedes Nieves. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de Córdoba. Observatorio Astronómico de Córdoba. Departamento de Astrofísica Estelar; Argentin