Retraction note: Sub-second periodicity in a fast radio burst (Nature, (2022), 607, 7918, (256-259), 10.1038/s41586-022-04841-8)

Retraction to: Naturehttps://doi.org/10.1038/s41586-022-04841-8 Published online 13 July 2022 The authors have retracted this article after identifying a crucial error: due to an unusual calibration problem, CHIME’s digital beams were incorrectly pointed when FRB 20191221A was detected. The sub-second periodicity that they associated with the putative fast radio burst FRB 20191221A was, in reality, a periodic signal from the known Galactic pulsar PSR J0248 + 6021. This directly impacts the conclusions drawn about the periodicity of FRB 20191221A and its possible origins. The authors note that the paper also reports the tentative detections of periodicity in two other sources, FRBs 20210206A and 20210213A, which are unaffected by the aforementioned short-lived digital mispointing issue. No other FRB detections published by CHIME/FRB were affected by this very unusual problem. The technical details for it have now been published by the author as a preprint ¹. All authors agree to this retraction.