GCN Circular 37893
Subject
GRB241025A: 1.3m DFOT optical afterglow detection
Event
Date
2024-10-26T16:20:45Z (a year ago)
From
ANSHIKA GUPTA at ARIES <anshika05180@gmail.com>
Via
Web form
Anshika Gupta, Amit K. Ror, Sneh Lata, Dorothy Museo, Kuntal Misra and Shashi B. Pandey (ARIES) report:
We observed the field of GRB 241025A detected by Swift-BAT (GCN 37859) with the 1.3m Devasthal Fast Optical Telescope (DFOT), located at the Devasthal Observatory of the Aryabhatta Research Institute of Observational Sciences (ARIES), India. The observations were started on 2024-10-25 at 14:13:20 UT, i.e., ~ 12.60 hours after the BAT trigger. We have taken multiple frames with an exposure time of 300 s in the R filter. We stacked the images after the alignment. We clearly detected optical afterglow in our stacked image within the error box of the enhanced Swift-XRT position by Goad et al. 2024 (GCN 37868). We obtained the following preliminary magnitude in the stacked image:
Date Start_UT T_start-T0 (hour) Filter Exp time (s) magnitude
===============================================================
2024-10-25 14:13:20 ~12.60 R 300*12 20.45 +- 0.05
Our detection is consistent with Jiang et al. 2024 (GCN 37862); Pereyra et al. 2024 (GCN 37865); Xu et al. 2024 (GCN 37866); SVOM Team(GCN 37871); Abdi et al. 2024 (GCN 37882); Watson et al. 2024(GCN 37889); Mohan et al. 2024(GCN 37890), and Vinko et al. 2024 (GCN 37891).
The magnitude is not corrected for the Galactic extinction in the direction of the burst.
Photometric calibration is performed using the standard stars from the USNO-B1.0 catalog. This circular may be cited.