Magnetised turbulence in protostellar discs - consequences for planet formation

by Dr Oliver Gressel (Nordita)

Friday 3 Feb 2012, 10:30 → 11:30 Europe/Stockholm

FA31

Rocky planets, and the cores of gas giant planets are believed to be assembled via the accumulation of so-called planetesimals. These are rocks of a few hundred metres to kilometres in size, floating around in the protostellar nebula. Being in a rather rough environment, they are subject to gravitational stirring from density fluctuations caused by the turbulent plasma. Implications include the collisional destruction of small bodies, and levels of large-scale spread of populations incompatible with the observed distribution within the asteroid belt. By contrast, a magnetically dead zone may provide a safe haven in which km-sized planetesimals can avoid mutual destruction.