Is There a Temperature Limit in Planet Formation at 1000 K?

• Published in: The Astrophysical journal Vol. 846; no. 1; pp. 48 - 53
• Main Authors: Demirci, Tunahan, Teiser, Jens, Steinpilz, Tobias, Landers, Joachim, Salamon, Soma, Wende, Heiko, Wurm, Gerhard
• Format: Journal Article
• Language: English
• Published: Philadelphia The American Astronomical Society 01.09.2017; IOP Publishing
• Subjects: Accretion disks; Agglomeration; astronomical databases: miscellaneous; Astrophysics; Dust; Extrasolar planets; High temperature; Laboratory experiments; Low speed; Low temperature; Planet formation; Planets; planets and satellites: formation; Protoplanetary disks; Protoplanets; Temperature; Terrestrial planets; Transition temperature; Transition temperatures
• ISSN: 0004-637X; 1538-4357
• DOI: 10.3847/1538-4357/aa816c

Dust drifting inward in protoplanetary disks is subject to increasing temperatures. In laboratory experiments, we tempered basaltic dust between 873 K and 1273 K and find that the dust grains change in size and composition. These modifications influence the outcome of self-consistent low speed aggregation experiments showing a transition temperature of 1000 K. Dust tempered at lower temperatures grows to a maximum aggregate size of 2.02 0.06 mm, which is 1.49 0.08 times the value for dust tempered at higher temperatures. A similar size ratio of 1.75 0.16 results for a different set of collision velocities. This transition temperature is in agreement with orbit temperatures deduced for observed extrasolar planets. Most terrestrial planets are observed at positions equivalent to less than 1000 K. Dust aggregation on the millimeter-scale at elevated temperatures might therefore be a key factor for terrestrial planet formation.