TITLE: GCN CIRCULAR NUMBER: 22058 SUBJECT: GROND observations of GRB 171027A: correction DATE: 17/10/27 11:49:56 GMT FROM: Patricia Schady at MPE/Swift P. Schady (MPE) reports: The upper limits reported in GCN #22056 were in fact calibrated against GROND zeropoints. The 3-sigma upper limits (AB) calibrated against PanSTARRS are in fact: g' > 22.2 r' > 22.2 i' > 21.2 z' > 21.0 The reported magnitudes are not corrected for the expected Galactic foreground extinction corresponding to a reddening of E_(B-V)=0.12 mag in the direction of the burst (Schlafly & Finkbeiner 2011).