A. Fitzsimmons reports the discovery of a comet in four 30-second survey images taken on Sep. 27 UT by ATLAS-HKO (T05), noting a condensed 9″ coma.  
While this object was still mentioned on the PCCP, we could observe this object with the Telescope.Live 0.7-m f/8 Ritchey-Chretien in Oria, Spain, and confirm the cometary features of this object. Later was this object assigned as comet C/2016 S1 (ATLAS) via M.P.E.C. 2021-T21, issued on 2021 oct. 3th.