Accretion onto Pre-Main-Sequence Stars

Accretion through circumstellar disks plays an important role in star formation and in establishing the properties of the regions in which planets form and migrate. The mechanisms by which protostellar and protoplanetary disks accrete onto low-mass stars are not clear; angular momentum transport by magnetic fields is thought to be involved, but the low-ionization conditions in major regions of protoplanetary disks lead to a variety of complex nonideal magnetohydrodynamic effects whose implications are not fully understood. Accretion in pre-main-sequence stars of masses 1 M (and in at least some 2-3-M systems) is generally funneled by the stellar magnetic field, which disrupts the disk at scales typically of…

• NS
  National Science Foundation
• NN
  National Natural Science Foundation of China