WAHHAJ Z., KOERNER D.W., RESSLER M.E., WERNER M.W., BACKMAN D.E. and SARGENT A.I.
Abstract (from CDS):
We present Keck images of the dust disk around β Pictoris at λ=17.9 µm that reveal new structure in its morphology. Within 1" (19 AU) of the star, the long axis of the dust emission is rotated by more than 10° with respect to that of the overall disk. This angular offset is more pronounced than the warp detected at 3".5 by the Hubble Space Telescope (HST) and is in the opposite direction. By contrast, the long axis of the emission contours ∼1".5 from the star is aligned with the HST warp. Emission peaks between 1".5 and 4" from the star hint at the presence of rings similar to those observed in the outer disk at ∼25" with the HST Space Telescope Imaging Spectrograph. A deconvolved image strongly suggests that the newly detected features arise from a system of four noncoplanar rings. Bayesian estimates based on the primary image lead to ring radii of 14±1, 28±3, 52±2, and 82±2 AU, with orbital inclinations that alternate in orientation relative to the overall disk and decrease in magnitude with increasing radius. We believe these new results make a strong case for the existence of a nascent planetary system around β Pic.