TITLE:   GCN CIRCULAR
NUMBER:  45916
SUBJECT: GRB 261011A: Optical followup from Sichuan South Observatory
DATE:    26/10/12 03:09:29 GMT
FROM:    Jiewei Zhao at SWIFAR, YNU <meow.jiewei.zhao@gmail.com>

Jiewei Zhao, Brajesh Kumar, Yuanpei Yang, Guowang Du (SWIFAR, YNU), Kai Liao, Xinyu Wang, Xing Yao, Yang Zeng and Chunlai Zhang (SSO) report:

We performed observations of the GRB 261011A field (Huang et al., GCN 45895; Cenko et al., GCN 45896; T0 at 2026-10-11T13:46:41) with 60cm telescope located at the Sichuan South Observatory (SSO), China. These observation were acquired from 2026-10-11T14:28:48.22 (~0.70 hours after the trigger) and continued ~2.40 hours. Multiple frames were acquired in L band with different exposure time. 

The optical counterpart reported by Swift-UVOT (Cenko et al., GCN 45896) and also confirmed by other facilities (O'Neill et al., GCN 45897; Fu et al., GCN 45898; Izzo et al., GCN 45899; Wu et al., GCN 45900; Yin et al., GCN 45901; Shi et al., GCN 45903; Aryan et al., GCN 45904; Arya et al., GCN 45907; Izzo et al., GCN 45909; Huang et al., GCN 45913; Bochenek et al., GCN 45914; Li et al., GCN 45915) was clearly detected in our frames and the preliminary photometry is following:

Start time[MJD], AB Magnitude, Filter   
61324.60334, 19.67 +/- 0.19, L
61324.62294, 20.10 +/- 0.14, L
61324.65458, 20.66 +/- 0.20, L

The given magnitudes are not corrected for the expected Galactic extinction.