TITLE: GCN CIRCULAR NUMBER: 6957 SUBJECT: GRB 071010B: Independent Confirmation of Break DATE: 07/10/20 23:45:41 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 continued our observation of GRB071010B (GCN 6871, Markwardt et al.), beginning at 10:53:09 UT on Oct 16, (5.58 days after the trigger), and at 10:54:39 on Oct 19 (8.58 days after the trigger). These observations reveal the optical afterglows again (GCN 6873, Oksanen et al.), and the Oct. 19 data confirms the break in the light curve reported earlier (GCN6935, Kann et al.). On the other hand, our Oct 16 photometry suggests that the break started around Oct. 16 or later. Photometry of the object is given below. t_start (UT) Filter exp (sec) R-mag err ----------------------------------------------------- Oct. 16, 10:53:09 R 17x300 21.2 0.1 Oct. 19, 10:54:39 R 8x300 22.0 0.3 This message may be cited.