Wednesday Lunch 1/29: Ian Stephens (BU)

The Morphology of the Magnetic Field of HL Tau

Dr. Ian Stephens (BU)
CAS 500, 12:10 pm, Tuesday January 28, 2014

The formation of disks around protostars is thought to be regulated through magnetic fields, and theoretical models suggest that the fractional polarization should be approximately 2-3%. Nevertheless, resolved observations of disks in T Tauri stars (TTS) have remained undetected and are constrained to have fractional polarization of less than 1%. However, with CARMA observations of HL Tau, we recently found the first detection of a resolved magnetic field about a TTS. These observations hint at a toroidal field, which suggests that accretion of T Tauri stars is controlled by magnetohydrodynamic turbulence driven by magnetorotational instability.