2018MNRAS.481...44F

The presence of a debris disc around the Gyr-old solar-type star ζ²Reticuli^ was suggested by the Spitzer infrared excess detection. Follow-up observations with Herschel/PACS revealed a double-lobed feature that displayed asymmetries both in brightness and position. Therefore, the disc was thought to be edge-on and significantly eccentric. Here we present ALMA/ACA observations in Band 6 and 7 which unambiguously reveal that these lobes show no common proper motion with ζ²Reticuli^. In these observations, no flux has been detected around ζ²Reticuli^ that exceeds the 3σ levels. We conclude that surface brightness upper limits of a debris disc around ζ²Reticuli^ are 5.7 µJy arcsec^–2 at 1.3 mm, and 26 µJy arcsec^–2 at 870 microns. Our results overall demonstrate the capability of the ALMA/ACA to follow-up Herschel observations of debris discs and clarify the effects of background confusion.