INVESTIGADORES
DI SISTO Romina Paula
congresos y reuniones científicas
Título:
The Centaur population
Autor/es:
R. P. DI SISTO; A. BRUNINI
Lugar:
Buzios
Reunión:
Simposio; Symposium No 229 de la IAU: Asteroids, Comets, Meteors; 2005
Institución organizadora:
IAU
Resumen:
We analyse here the Centaur population as a group of objects withperihelion distances (q) less than 30 AU, formed by objects enteringthe planetary zone from the Scattered Disk (SD) and objects leavingthe inner solar system. We perform a numerical integration of 95 realscattered disk objects (SDOs) extracted from the Minor Planet Centerdatabase and 905 clones. We consider them as massless particles underthe gravitational influence of the Sun and the four giant planets.The system evolves for 4.5 Gy or until a particle collides with aplanet, reaches a semimajor axis a > 1000 AU or enter the regioninside Jupiter´s orbit (r<5.2 AU) where it is considered to go over aJupiter Family Comet (JFC). At this stage the objects evolve as JFCsup to reach again the Centaur zone contributing to this population butnow as a JFC. We evaluate also, the contribution of escaped Hildas andTrojan asteroids. SDOs have in the Centaur zone a mean life time of72 My, although this number fall with a decrease of q. After thisincursion, 22 % of them enter the JFC zone and return to the Centaurzone in their way to ejection having there a mean lifetime of 1.2My. The mean lifetimes of escaped Hildas in that region is 2.3 My. Wefound that the greater contribution to the Centaur population comesfrom the SD. On the other hand, the majority (more than 80 %) ofdiscovered Centaurs have q < 20 AU. Therefore we guess that theobserved Centaurs are more likely to be evolved objects coming fromthe SD and there must be lots of Centaurs not already discovered withlarge perihelion distances.