Debris discs around nearby Solar analogues

TL;DR

This study conducted an unbiased survey of debris discs around nearby Sun-like stars, confirming a disc around HD 30495 and suggesting such discs are not commonly missed, with implications for models of dust evolution.

Contribution

First unbiased millimetre survey of debris discs around nearby Sun-like stars, confirming a disc around HD 30495 and constraining the population of cold discs.

Findings

Disc around HD 30495 has a dust mass of 0.008 Earth masses.

No large population of cold debris discs around Sun-like stars detected.

Survey data fit models assuming steady state or stirred dust production.

Abstract

An unbiased search for debris discs around nearby Sun-like stars is reported. Thirteen G-dwarfs at 12-15 parsecs distance were searched at 850 $\umu$m wavelength, and a disc is confirmed around HD 30495. The estimated dust mass is 0.008 M$_{\oplus}$ with a net limit $\la 0.0025$ M$_{\oplus}$ for the average disc of the other stars. The results suggest there is not a large missed population of substantial cold discs around Sun-like stars -- HD 30495 is a bright rather than unusually cool disc, and may belong to a few hundred Myr-old population of greater dust luminosity. The far-infared and millimetre survey data for Sun-like stars are well fitted by either steady state or stirred models, provided that typical comet belts are comparable in size to that in the Solar System.