A Planet as the Possible Cause of the HD 181327 Debris Disk Asymmetry

TL;DR

This paper suggests that a planet between 2-5 Jupiter masses at 62 au could cause the observed asymmetry in the debris disk of HD 181327, with implications for planet detection.

Contribution

It demonstrates how a planet can produce and sustain the observed disk asymmetry and predicts the planet's location and observability.

Findings

A 2-5 Jupiter-mass planet can create the disk asymmetry.

The asymmetry is less visible at larger particle sizes.

The planet is likely along the line connecting the star and the feature.

Abstract

The debris disk around HD 181327 shows a significant asymmetry in its surface brightness profile when viewed in visible light. Observations from the Hubble Space Telescope STIS instrument show an arc of approximately 90 degrees of higher optical depth at a distance of 84 au from the star. We find that a 2-5 Jupiter-mass planet on a circular orbit at 62 au can produce and maintain a similar feature if the collisional lifetime of dust in the disk is at least 25 kiloyears, and smaller mass planets can produce similar results on longer timescales. We also find that the surface brightness asymmetry is much less pronounced at larger particle sizes, which may account for the fact that observations of HD181327 at longer wavelengths have not reported such an arc. We predict that if a planet is producing the arc in question, the planet is along the line joining the star to the feature, and make some estimates of its observability.