lundi 3 février 2014, par Johan Olofsson (Max Planck Institute for Astronomy, Heidelberg, Germany )
Mardi 25 février 2014 à 11h00 , Lieu : Salle de conférence du bât 17
I will present recent results regarding two peculiar objects in which planetary formation is most likely on-going. First, I will discuss in detail the 7 Myr old transition disk around TCha. With a large interferometric dataset, we are able to finely characterize the geometry of this transition disk, and revisit the previous detection of a candidate companion found to be in the gap. Nonetheless, the disk displays several features indicating that giant planet formation is on-going. Second, I will discuss the case of the 10-16 Myr old debris disk around HD113766A. With Herschel/PACS and VLTI/MIDI observations we demonstrate that the debris disk is twofold, with an inner dusty belt close to the star. Modeling results, such as the size of this belt and specific mineralogical markers indicate that we are witnessing the outcome of a collision between differentiated planetesimals. Terrestrial planet formation is known to be a highly unstable period of time and may explain our findings.