TITLE: GCN CIRCULAR NUMBER: 26059 SUBJECT: GRB 191019A: Nanshan-0.6m optical observations DATE: 19/10/22 13:58:53 GMT FROM: Dong Xu at NAOC/CAS Z.P. Zhu, B.Y. Yu, D. Xu (NAOC), X. Gao (Urumqi No.1 Senior High School) report: We observed the field of GRB 191019A (Simpson et al., GCN 26031) using the 0.6m NEXT telescope located at Nanshan, Xinjiang, China. Observations started at 15:34:01 UT (i.e., 21.5 min after the BAT trigger) and ended at 18:22:51 UT on 2019-10-19, and a series of 60 s, 200 s, 300 s Sloan r-band frames were obtain in a high airmass. A source is detected in our images at the XRT position (Osborne et al., GCN 26043), which is already present in Pan-STARRS with m(r) = 19.12 +/- 0.01. The source had m(r) = 18.96 +/- 0.10 at the beginning and decayed to m(r) = 19.19 +/- 0.10 in about an hour. Because the flux difference is small and observations were carried out in high airmass, it's not clear if there is a GRB afterglow contribution. Our measurements are in agreement with that by NOT (Perley et al., GCN 26039; Fynbo et al., GCN 26041) and GROND (Guelbenzu et al., GCN 26042).