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

TL;DR

This study uses polarized light imaging to observe dust around a close-in stellar companion in the HD 142527 transition disk, revealing potential dust accretion and providing insights into planet formation processes.

Contribution

First direct detection of dust around a close-in companion in a transition disk using polarized light imaging, suggesting ongoing accretion and complex disk-companion interactions.

Findings

Detected the companion in total intensity consistent with expectations.

Identified a polarized point-source possibly indicating dust near the companion.

Suggested dust may be falling onto or orbiting the companion, affecting mass estimates.

Abstract

When giant planets form, they grow by accreting gas and dust. HD 142527 is a young 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 an attempt to directly detect the dusty counterpart to this accreted gas, we have observed 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 and show that its position and photometry are generally consistent with the expected values. We also detect a point-source in polarized light that may be spatially separated by \about a few AU from the location of the companion in total intensity. This suggests that dust is likely falling onto or orbiting the companion. Given the possible contribution of scattered light from this dust to previously reported photometry of the companion, the current mass limits should be viewed as upper limits only. If the dust near the companion is eventually confirmed to be spatially separated, this system would resemble a scaled-up version of the young planetary system inside the gap of the transition disk around LkCa 15.