The motion of chondrules and other particles in a protoplanetary disc   with temperature fluctuations
  We consider the mechanism of photophoretic transport in protoplanetary disks that are optically thick to radiation. Here, photophoresis is not caused by the central star but by temperature fluctuations that subject suspended solid particles, including chondrules, to non-isotropic thermal radiation within the disk. These short-lived temperature fluctuations can explain time-of-flight size sorting and general number density enhancements. The same mechanism will also lead to velocity fluctuations of dust aggregates beyond $100\,\mathrm{m\,s^{-1}}$ for mm-sized particles in protoplanetary disks. Applying this in future research will change our understanding of the early phases of collisional dust evolution and aggregate growth as particles cross the bouncing barrier and as mass transfer rates are altered. 
Christoph Loesche and Gerhard Wurm and Thorben Kelling and Jens Teiser   and Denton S. Ebel
astro-ph.EP astro-ph.SR