On the Relationship Between Debris Disks and Planets

TL;DR

This study investigates the correlation between debris disks and planets by analyzing infrared data from a large sample of stars, finding only a marginal association and no significant difference in disk brightness.

Contribution

It provides the largest comparative analysis to date of debris disks around planet-hosting stars versus stars without detected planets, using survival analysis techniques.

Findings

Debris disks are marginally more common around stars with planets.

The brightness of debris disks does not significantly differ between stars with and without planets.

Detection of planets via radial velocity does not strongly predict debris disk presence.

Abstract

Dust in debris disks is generated by collisions among planetesimals. The existence of these planetesimals is a consequence of the planet formation process, but the relationship between debris disks and planets has not been clearly established. Here we analyze Spitzer/MIPS 24 and 70 micrometer data for 150 planet-bearing stars, and compare the incidence of debris disks around these stars with a sample of 118 stars around which planets have been searched for, but not found. Together they comprise the largest sample ever assembled to deal with this question. The use of survival analysis techniques allows us to account for the large number of non-detections at 70 micrometer. We discovered 10 new debris disks around stars with planets and one around a star without known planets. We found that the incidence of debris disks is marginally higher among stars with planets, than among those without, and that the brightness of the average debris disk is not significantly different in the two samples. We conclude that the presence of a planet that has been detected via current radial velocity techniques is not a good predictor of the presence of a debris disk detected at infrared wavelengths.