School of Mathematical Sciences

Oort Cloud Comet Dynamics: The Synergy Between Passing Stars and the Galaxy menu

Oort Cloud Comet Dynamics: The Synergy Between Passing Stars and the Galaxy

Speaker: 
Dr. Marc Fouchard (LAL-IMCCE/Universitée de Lille)
Date/Time: 
Fri, 15/10/2010 - 15:30
Room: 
Maths 103

The long period comets are likely to come from the furthest region from the Sun of the Solar System: the Oort cloud.
At such distances from the Sun, the comet trajectories are affected by the stars which come close to the Sun and by
the gravitational influence of the entire Galaxy. It appears that a strong synergy is at work between these two effects allowing the
injection of Oort cloud comets in an observable region defined by heliocentric distance smaller than 5 au.  This synergy is characterised by two different mechanisms: one acts on long time scale, i.e. several 100 Myr, and one during the last orbital period of the observable comets. After a description of these mechanisms we will discuss their implications on our knowledge of the Oort cloud. In particular, the short term synergy may affect significantly the location of the Oort cloud. We will then show how the future astrometric mission GAIA
will help to address this question.