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ABSTRACTS - O8% Fteclassical the of 80%) to LHB the (After Stage While Migration Phase)

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ABSTRACTS - O8% Fteclassical the of 80%) to LHB the (After Stage While Migration Phase) RevMexAA (Serie de Conferencias), 44, 129–225 (2014) ABSTRACTS PLANETARY SYSTEMS A DYNAMICAL MECHANISM TO PRODUCE HIGH-INCLINATIONS TNOS P. I. O. Brasil1,2, R. S. Gomes2,3, and D. Nesvorn´y2 THE USE OF THE MATHEMATICA SOFTWARE IN THE STUDY OF PLANETARY We discuss the dynamical formation of small Solar DYNAMICS System objects beyond Neptune. The discovery of N. F. Aguero1 and T. A. Michtchenko2 the first trans-Neptunian object (TNO) − except for Pluto and Charon − is relatively recent (1992QB1). This work presents a study on how techniques pro- Many unpredicted dynamical and physical features vided by the algebraic manipulation software Math- not predicted in past theoretical models and are now ematica can be used in planetary dynamics inves- showing up. Among them, we note the existence of tigations. The discovery of extra-solar planets or- many high-inclined orbits with respect to the eclip- biting other stars has been one of the major break- itc plane (where all Solar System bodies supposedly throughs in astronomy of the past decades, chang- have formed). ing our view on the features of planetary systems, The aim of this work is to show a dynamical mainly drawn from the observation of the Solar Sys- pathway from the primordial planetesimal disk to tem. Today, over 1000 exoplanets are known and high inclinations orbits in the trans-Neptunian re- the Kepler satellite has recently identified over 3000 gion. The main mechanism requires that scattered additional candidates, most of them still waiting for planetesimals are captured into some exterior mean confirmation. We have learned that exoplanets are motion resonance (MMR) with Neptune and then be much more diverse when compared to our own So- trapped into the Kozai resonance as well. After that, lar System. Thus, the implementation of advanced some planetesimals may access a resonance hibernat- manipulation techniques can be of great importance ing mode in which the planesimal is barely locked in for the investigation of such unusual configurations resonance. We show that only a few percent of all of these new worlds. We chose Mathematica, a soft- scattered planetesimals would access the hibernating ware that has been increasingly used worldwide due mode. But, once this mechanism is active, ∼ 100% to its great analysis power. of the particles would escape both resonances while The case that we focus is the 2/1 mean-motion Neptune is in its final migration stage (after the LHB Editors: A. Mateus, J. Gregorio-Hetem & R. Cid Fernandes resonance in the two-planet systems. Based on the phase). Mathematica platform, we present animations of the Our results could explain at least a portion (up orbits of the Neptune-Pluto system and exoplanets to 80%) of the classical hot population, defined by o in the 2:1 mean-motion resonance over a short-period a2:3 <a<a1:2, i > 5 , and q > 36au. Previ- of time. The visualization of this problem can be ous results indicate that this mechanism is the most XIV Latin American Regional IAU Meeting (Florianópolis/SC, Brazil, 25-30 November 2013) very important to an initial understanding of dynam- likely to form the detached objects close to MMR ical proprieties of resonant planetary systems and with Neptune as, for example, 2004XR190 (Gomes, their stability. 2011, Icarus 215, 661). We have determined the most probable regions, in the orbital elements space 1 IAG-USP - Instituto de Astronomia, Geof´ısica e (a, e, i), where detached objects would form close to Ciˆencias Atmosf´ericas da Universidade de S˜ao Paulo (nfa- 2:5 and 1:3 MMRs (Brasil, Gomes & Soares, 2013 - [email protected]). submitted to A&A). 2 IAG-USP - Instituto de Astronomia, Geof´ısica e Ciˆencias Atmosf´ericas da Universidade de S˜ao Paulo (ta- 1 [email protected]). Instituto Nacional de Pesquisas Espaciais, Divis˜ao de Mecˆanica Espacial e Controle - INPE/DMC. 2 Southwest Research Institute, Departments of Space Stud- ies and Space Operations - SwRI/DSSSO. 3 Observat´orio Nacional, Grupo de Pesquisa em Astromomia - ON/GPA. 129 130 ABSTRACTS P. Cuartas-Restrepo1, M. Melita2, J. Zuluaga1, J. Hoyos3, and M. Sucerquia1 The rotation and thermal evolution of a planet plays a main role in the planetary magnetic field evolu- STABLE LOW-ALTITUDE ORBITS AROUND tion. The rotation period determines properties like GANYMEDE CONSIDERING A DISTURBING the regime of the planetary dynamo and its inten- BODY IN A CIRCULAR ORBIT sity. This is crucial for a planet to keep its reservoir J. Cardoso dos Santos1, J. P. S. Carvalho2, and R. 2 of volatile material like water, protected against the V. de Moraes erosive action of the stellar wind and cosmic rays. Planets orbiting dwarf stars are tidally affected by Some missions are being planned to visit Ganymede their host, this determines the final rotation period like the Europa Jupiter System Mission that is a (resonance) or the tidal locking of the planet, espe- cooperation between NASA and ESA to insert the cially during the very first Myr. At the same time spacecraft JGO (Jupiter Ganymede Orbiter) into this first period of the planet history is the most af- Ganymedes orbit. This comprehension of the dy- fected by the magnetic activity of the host star. We namics of these orbits around this planetary satellite calculate the rotation and tidal evolution of planets is essential for the success of this type of mission. and combine this with a thermal evolution model to Thus, this work aims to perform a search for low- know how this very first stages of the planetary evo- altitude orbits around Ganymede. An emphasis is lution finish with an stable and protective planetary given in polar orbits and it can be useful in the plan- magnetic field or with an unprotected planet. ning of space missions to be conducted around, with respect to the stability of orbits of artificial satel- 1 Instituto de F´ısica - FCEN, Universidad de Antioquia, lites. The study considers orbits of artificial satel- Medell´ın, Colombia. lites around Ganymede under the influence of the 2 Instituto de Astronom´ıa y F´ısica del Espacio - IAFE, Buenos third-body (Jupiter’s gravitational attraction) and Aires, Argentina. 3 Departamento de Ciencias B´asicas, Universidad de Medell´ın, the polygenic perturbations like those due to non- Medell´ın, Colombia. uniform distribution of mass (J2 and J3) of the main body. A simplified dynamic model for these pertur- bations is used. The Lagrange planetary equations are used to describe the orbital motion of the arti- ficial satellite. The equations of motion are devel- IMPROVEMENT OF TNO’S EPHEMERIS IN oped in closed form to avoid expansions in eccentric- THE CONTEXT OF STELLAR OCCULTATIONS ity and inclination. The results show the argument J. Desmars1, F. Braga-Ribas1, R. Vieira-Martins1, of pericenter circulating. However, low-altitude (100 J. I. B. Camargo1, and M. Assafin2 and 150 km) polar orbits are stable. Another or- Editors: A. Mateus, J. Gregorio-Hetem & R. Cid Fernandes bital elements behaved variating with small ampli- Trans-Neptunian Objects are distant, faint and tudes. Thus, such orbits are convenient to be ap- poorly known solar system objects. Stellar occulta- plied to future space missions to Ganymede. Ac- tions are currently, the only way to precisely deter- ◦ knowledgments: FAPESP (processes n 2011/05671- mine some physical characteristics of these objects, 5, 2012/12539-9 and 2012/21023-6). such as the shape/size, the multiplicity or an even- XIV Latin American Regional IAU Meeting (Florianópolis/SC, Brazil, 25-30 November 2013) tual atmosphere. The prediction of stellar occulta- 1 Group on Orbital Dynamics and Planetology, S˜ao tions requires both accurate astrometry of stars and Paulo State University (UNESP), Guaratinguet´a, Brazil. ([email protected]). accurate ephemeris. 2 Institute of Science and Technology, Federal University of The current methods of prediction use a con- S˜ao Paulo (UNIFESP), S˜ao Jos´edos Campos, Brazil. stant offset compared to JPL ephemeris. The off- set is calculated from the most recent observations as the mean difference between observations and the ephemeris. This method assumes that the offset re- mains constant over a certain period. TIDAL, THERMAL AND MAGNETIC In this study, we perform a new ephemeris with EVOLUTION OF TERRESTRIAL available observations and observations done for off- EXOPLANETS IN THE HABITABLE ZONE OF set determination. In this context, we have devel- DWARF STARS oped a dynamical model of the motion of asteroids ABSTRACTS 131 (NIMA), fitted to observations and determined a find that, there could be a collision of a meteorite be- new ephemeris. fore, during, or after the Asteroid 2012 DA14 pass- The difference between NIMA and JPL ing by, the same way that happens with meteorite ephemerides is close to the offset at the date of ob- showers, which can last several days. Therefore, it servations but this difference then varies over time, would be very interesting to look for asteroid frag- according to a periodic one-year term and a secu- ments also, close to the larger fragments, more easily lar term. For some objects, the offset method may found. remain accurate when the time between observa- tions and occultation is short or when the offset’s 1 Federal Institute of Parana - IFPR, Brazil(jania.duha@ifpr. variations remain small. For other TNOs, the dif- edu.br). 2 Federal Institute of Amazonas - IFAM, Brazil. ference sharply increases making inaccurate predic- tions in the future. Consequently, new ephemerides should be used to make predictions. Finally, occul- tations also provide accurate astrometric positions and therefore new constraints on the TNO’s motion. We analyze the contribution of previous occultations ATLAS OF THE THREE BODY RESONANCES in the improvement of TNO’S ephemerides.
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