The Twisted Magnetic Field of the Protobinary L483

Abstract

We present H-band (1.65 μm) and SOFIA HAWC+ 154 μm polarization observations of the low-mass core L483. Our H-band observations reveal a magnetic field that is overwhelmingly in the E–W direction, which is approximately parallel to the bipolar outflow that is observed in scattered IR light and in single-dish 12CO observations. From our 154 μm data, we infer a ∼45° twist in the magnetic field within the inner 5″ (1000 au) of L483. We compare these new observations with published single-dish 350 μm polarimetry and find that the 10,000 au scale H-band data match the smaller-scale 350 μm data, indicating that the collapse of L483 is magnetically regulated on these larger scales. We also present high-resolution 1.3 mm Atacama Large Millimeter/submillimeter Array data of L483 that reveals it is a close binary star with a separation of 34 au. The plane of the binary of L483 is observed to be approximately parallel to the twisted field in the inner 1000 au. Comparing this result to the ∼1000 au protostellar envelope, we find that the envelope is roughly perpendicular to the 1000 au HAWC+ field. Using the data presented, we speculate that L483 initially formed as a wide binary and the companion star migrated to its current position, causing an extreme shift in angular momentum thereby producing the twisted magnetic field morphology observed. More observations are needed to further test this scenario.