TITLE: GCN CIRCULAR NUMBER: 27806 SUBJECT: GRB 200524A: 1.3m DFOT Optical Observation of ZTF20abbiixp DATE: 20/05/24 22:32:48 GMT FROM: Amit Kumar at ARIES, India A. Kumar (ARIES), S. B. Pandey (ARIES), A. Ghosh (ARIES), Dimple (ARIES), K. Misra (ARIES), R. Gupta (ARIES), K. Chand (ARIES) and A. Aryan (ARIES) report: We observed the optical afterglow of GRB 200524A (F. F. Dirirsa et al., GCN 27797, Evans et al., GCN 27798) with the 1.3m Devasthal Fast Optical Telescope (DFOT) at Aryabhatta Research Institute of Observational Sciences (ARIES), Nainital (India), from 2020-05-24T19:50:12 UTC (corresponding to ~14.770 hours after the burst). We observed 5 frames each of 300 seconds in Bessell I filter. In the stacked image, we clearly detected the optical afterglow of GRB 200524A (detected by Ho et al., GCN 27799, see also Kumar et al., GCN 27800, Rumyantsev et al., GCN 27802 and Sanwal et al., GCN 27803). The observed magnitude is as follows: T_start-T0 (hours) Start Date (UTC) End Date (UTC) Filter Magnitudes (mag) --------------------------------------------------------------------------------------------------------------- 14.770 2020-05-24T19:50:12 2020-05-24T20:32:37 I 20.33 +- 0.07 Photometry is done based on the USNO-B1.0 catalog. The quoted magnitude is not corrected for Galactic extinction.