TITLE:   GCN CIRCULAR
NUMBER:  42334
SUBJECT: GRB 251013C: Liverpool Telescope observations
DATE:    25/10/17 21:03:54 GMT
FROM:    A. Bochenek at Liverpool John Moores University <a.m.bochenek@2023.ljmu.ac.uk>

A. Bochenek and D. A. Perley (LJMU) report:

 

We observed the field of GRB 251013C (Fermi GBM team, GCN 42221; Rakotondrainibe et al., GCN 42222) using the IO:O optical camera on the 2m robotic Liverpool Telescope. We obtained 60s exposures in the SDSS ugriz filters, starting on 2025-10-14 01:46:49, about 8.1h after Fermi trigger.

 

We report detections in all bands, at the position of the optical afterglow first reported by Palmerio et al., GCN 42223:

 

MJD (start)         T_mid-T_0        Filter       Mag. (AB)

60962.07711        8.20 h              u     19.07 ± 0.10

60962.07418        8.13 h              g     18.62 ± 0.04

60962.07517        8.15 h              r     18.36 ± 0.02

60962.07614        8.17 h              i     18.14 ± 0.03

60962.07877        8.24 h              z     18.00 ± 0.03

 

The photometry for griz filters was calibrated using nearby PanSTARRS secondary standards, while u-band photometry was calibrated using the SDSS catalogue. The photometry is not corrected for extinction.