FOR 759:  The Formation of Planets: The Critical First Growth Phase

• Subject Area: Physics ; Geosciences
• Term: from 2006 to 2014
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 24367531

The formation of planets is one of the key questions in astrophysics. The first step in this process is the coagulation of dust: The growth from submicron dust particles to ever larger aggregates ultimately leading to the formation of multi-kilometer sized "planetesimals". Once these planetesimals are formed, gravitational interaction starts to dominate over all other forces, and eventually, leads to the formation of rocky planets. In our Research Unit we focus on the first stage in the planet formation scenario, i.e. on the growth process from dust to planetesimals.
This stage suffers from a large number of unsolved mysteries, many of which are critical to our understanding of the planetesimal formation process as a whole. Among them are: The seemingly insurmountable "meter-size barrier" for the collisional growth of particles, the poorly understood causes of the complex mineralogical structure of meteorites, and the apparent lack of correlation between certain observational signatures of grain evolution and the age of the parent star. In spite of the clear connection between these issues, they have mostly been studied by somewhat separate scientific communities. In particular the meteoritics/cosmochemistry/astromineralogy community, the collision experimentalists, the theoretical astrophysicists and the observational astronomers have had relatively little cross-field collaboration in the past. The most promising option to solve many questions surrounding the growth from dust to planetesimals is to unite these various communities in a joint research effort. This is the purpose of the Research Unit.

• DFG Programme: Research Units
• International Connection: Austria

Projects

• Central project (Applicant Kley, Wilhelm )
• Charge transfer in dust-agglomerate collisions and the efficiency of electrostatic secondary agglomeration (Applicant Blum, Jürgen )
• Dust Processing during the Gravitational Collapse of Particle Heaps (Applicant Klahr, H. Hubertus )
• Evolution of the mineralogical and chemical composition of pre-planetary disks (Applicant Tscharnuter, Werner M. )
• Growth Below the Meter-Size Barrier: Collision Experiments in the Bottleneck of Planet Formation (Applicant Blum, Jürgen )
• Growth beyond the meter-barrier: Aggregation and fragmentation in single and multiple high velocity collisions (Applicant Wurm, Gerhard )
• Influence of high-temperature processes on the growth of protoplanetary dust aggregates and planetesimals (Applicant Blum, Jürgen )
• Initial conditions of the birthplaces of planets (Applicant Kley, Wilhelm )
• Modeling the evolution of the dust population in protoplanetary disks (Applicant Dullemond, Cornelis Petrus )
• Planetesimal precursors in turbulent protoplanetary disks (Applicants Klahr, H. Hubertus ;  Kley, Wilhelm )
• Prediction of observable quantities tracing the process of planetesimal formation (Applicant Wolf, Sebastian )
• Simulations of Agglomerate Collisions with Smooth Particle Hydrodynamics - Realistic Material Properties and Sticking, Bouncing and Fragmentation Statistics (Applicant Kley, Wilhelm )
• Thermal annealing of silicates in protoplanetary disks - Laboratory data and modelling (Applicant Lattard, Dominique )

• Spokesperson: Professor Dr. Wilhelm Kley (†)
• Deputies: Professor Dr. Cornelis Petrus Dullemond; Professor Dr. Mario Trieloff