Dust grains are small solid particles, typically measuring between 0.1 micrometers to a few hundred micrometers, found in various astronomical environments, including protoplanetary disks. These grains play a crucial role in the formation of planetary systems by serving as the building blocks for larger bodies through processes like coagulation and accretion. They are also essential in the gravitational instability model, where their presence can lead to local density enhancements that trigger the formation of planets.
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