A Survey for Massive Giant Planets in Debris Disks with Evacuated Inner Cavities

TL;DR

This survey used high-contrast imaging to search for massive giant planets in debris disks with evacuated inner cavities, aiming to understand if such planets are responsible for clearing these regions.

Contribution

It provides the first direct imaging constraints on the presence of massive planets in debris disks with large inner cavities, setting upper mass limits and informing planet formation theories.

Findings

No planets were detected in the surveyed disks.

The upper mass limits suggest planets >3-7 Jupiter masses are absent.

Results support the idea that giant planets are confined within 15 AU.

Abstract

The commonality of collisionally replenished debris around main sequence stars suggests that minor bodies are frequent around Sun-like stars. Whether or not debris disks in general are accompanied by planets is yet unknown, but debris disks with large inner cavities - perhaps dynamically cleared - are considered to be prime candidates for hosting large-separation massive giant planets. We present here a high-contrast VLT/NACO angular differential imaging survey for eight such cold debris disks. We investigated the presence of massive giant planets in the range of orbital radii where the inner edge of the dust debris is expected. Our observations are sensitive to planets and brown dwarfs with masses >3 to 7 Jupiter mass, depending on the age and distance of the target star. Our observations did not identify any planet candidates. We compare the derived planet mass upper limits to the minimum planet mass required to dynamically clear the inner disks. While we cannot exclude that single giant planets are responsible for clearing out the inner debris disks, our observations constrain the parameter space available for such planets. The non-detection of massive planets in these evacuated debris disks further reinforces the notion that the giant planet population is confined to the inner disk (<15 AU).