TITLE: GCN CIRCULAR NUMBER: 33387 SUBJECT: GRB 230228A: OSN optical upper limit DATE: 23/03/01 11:21:01 GMT FROM: Youdong HU at IAA-CSIC huyoudong072@hotmail.com
Y.-D. Hu, V. Casanova, E. Fernandez-Garcia, A. J. Castro-Tirado, I. Perez-Garcia, M.D. Caballero-Garcia, R. Sanchez-Ramirez, S. Guziy (IAA-CSIC), on behalf of a larger collaboration, report:
Following the detection of GRB 230228A by Swift (Dichiara et al. GCN 33378), we triggered the 0.9m OSN telescope in Granada (Spain) starting on Feb. 28 at 19:34:03 UT (~13.7 hrs post burst). Ten images covering the burst error region were taken in the I-band. No optical afterglow is detected in the stacked image down to I=20.2 mag. These results are in agreement with the non-detection reported by Lim et al. (GCNC 33380), Lu et al. (GCNC 33381) and Belkin et al. (GCNC 33383).
We thank the staff at OSN for their excellent support.