Polarized Light Imaging of the HD 142527 Transition Disk with the Gemini Planet Imager: Dust around the Close-in Companion

摘要

When giant planets form, they grow by accreting gas and dust. HD 142527 is ayoung star that offers a scaled-up view of this process. It has a broad,asymmetric ring of gas and dust beyond \about 100 AU and a wide inner gap.Within the gap, a low-mass stellar companion orbits the primary star at just\about 12 AU, and both the primary and secondary are accreting gas. In anattempt to directly detect the dusty counterpart to this accreted gas, we haveobserved HD 142527 with the Gemini Planet Imager in polarized light at $Y$ band(0.95-1.14 \microns). We clearly detect the companion in total intensity andshow that its position and photometry are generally consistent with theexpected values. We also detect a point-source in polarized light that may bespatially separated by \about a few AU from the location of the companion intotal intensity. This suggests that dust is likely falling onto or orbiting thecompanion. Given the possible contribution of scattered light from this dust topreviously reported photometry of the companion, the current mass limits shouldbe viewed as upper limits only. If the dust near the companion is eventuallyconfirmed to be spatially separated, this system would resemble a scaled-upversion of the young planetary system inside the gap of the transition diskaround LkCa 15.