Gemini-LIGHTS: Herbig Ae/Be and massive T-Tauri protoplanetary disks imaged with Gemini Planet Imager

TL;DR

This study presents a comprehensive near-infrared polarized light survey of 44 protoplanetary disks around Herbig Ae/Be and T-Tauri stars, revealing disk structures, companions, and correlations with system parameters to understand disk evolution and planet formation.

Contribution

It provides a less-biased, complete sample of protoplanetary disks observed with Gemini GPI, detecting polarized scattered light in 80% of targets and discovering new companions and disk features.

Findings

Polarized light detected in 80% of targets.

Companions found around 47% of systems, including new objects.

Correlations between polarized flux, IR excess, and stellar mass.

Abstract

We present the complete sample of protoplanetary disks from the Gemini- Large Imaging with GPI Herbig/T-tauri Survey (Gemini-LIGHTS) which observed bright Herbig Ae/Be stars and T-Tauri stars in near-infrared polarized light to search for signatures of disk evolution and ongoing planet formation. The 44 targets were chosen based on their near- and mid-infrared colors, with roughly equal numbers of transitional, pre-transitional, and full disks. Our approach explicitly did not favor well-known, "famous" disks or those observed by ALMA, resulting in a less-biased sample suitable to probe the major stages of disk evolution during planet formation. Our optimized data reduction allowed polarized flux as low as 0.002% of the stellar light to be detected, and we report polarized scattered light around 80% of our targets. We detected point-like companions for 47% of the targets, including 3 brown dwarfs (2 confirmed, 1 new), and a new super-Jupiter mass candidate around V1295 Aql. We searched for correlations between the polarized flux and system parameters, finding a few clear trends: presence of a companion drastically reduces the polarized flux levels, far-IR excess correlates with polarized flux for non-binary systems, and systems hosting disks with ring structures have stellar masses $<$ 3 Msun. Our sample also included four hot, dusty "FS CMa" systems and we detected large-scale ($>100$ au) scattered light around each, signs of extreme youth for these enigmatic systems. Science-ready images are publicly available through multiple distribution channels using a new FITS file standard jointly developed with members of the VLT/SPHERE team.