TITLE: GCN CIRCULAR NUMBER: 38371 SUBJECT: GRB 241128A: 1.5m OSN optical afterglow detection DATE: 24/11/28 21:15:38 GMT FROM: Youdong HU at INAF-OAB <huyoudong072@hotmail.com> Y.-D. Hu (INAF-OAB), V. Casanova, E. Fernandez-Garcia, A. J. Castro-Tirado, S.-Y. Wu, I. Perez-Garcia, M.D. Caballero-Garcia, R. Sanchez-Ramirez, S. Guziy (IAA-CSIC) and G. Garcia-Segura (UNAM), on behalf of a larger collaboration, report: Following the detection of GRB 241128A by Swift (Brivio et al. GCN 38367), we triggered the 1.5m OSN telescope in Granada (Spain) starting on Nov 28, 18:19 UT (~2.1 hrs post burst) in R & I-bands. An uncatalogued object is detected within the XRT error circle (Page et al. GCNC 38368) with R=19.3+-0.1 mag, at coordinates RA(J2000) = 18:14:53.55, DEC(J2000) = +33:26:20.32, which we proposed as the GRB 241128A optical afterglow. Spectroscopic observations are encouraged. We thank the staff at OSN for their excellent support. View this GCN Circular online at https://gcn.nasa.gov/circulars/38371. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0LW...