Measurements of polarized 1.25-mm continuum emission from the accretion disk of the T Tauri star HL Tau show that the magnetic field inside the disk cannot be dominated by a vertical component, and that a purely toroidal field also does not fit the data; this suggests that the role of the magnetic field in the accretion of a T Tauri star is more complex than the current theoretical understanding.
- Ian W. Stephens
- Leslie W. Looney
- Ramprasad Rao
