TITLE: GCN CIRCULAR NUMBER: 6991 SUBJECT: GRB 071025: I-detection, R-dropout? DATE: 07/10/25 05:43:23 GMT FROM: Myungshin Im at Seoul Nat U M. Im, I. Lee (Seoul National University), and Y. Urata (Saitama University) on behalf of the EAFON team: Using the Mt. Lemmon (Arizona, US) 1.0m telescope operated by the Korea Astronomy Space Science Institute, we observed GRB071025, beginning at 04:35 UT on Oct 25. We have a clear detection of the afterglow in 300 secs frame taken in I-band (GCN6987, Rykoff et al.), but no detection at all in B, V, R-band with the same exposure time. The non-detection R-band suggests that the GRB is likely a R-band dropout at z ~ 6. This message may be cited. We acknowldege the help of the LOAO operators, J.H. Yoon, for this observation.