TITLE:   GCN CIRCULAR
NUMBER:  43305
SUBJECT: GRB 260102A: LCO optical upper limits
DATE:    26/01/02 15:02:54 GMT
FROM:    SVOM_group <svomgroup@bao.ac.cn>

A. Saccardi (CEA/Irfu), C. Wu, W. Xie (NAOC), W. Tan (IHEP) report on behalf of the SVOM mission team:

We observed the field of the SVOM GRB 260102A (Xie et al., GCN 43295) with the LCO 1m telescope at McDonald Observatory equipped with the Sinistro instrument.

Our observation started on 2026-01-02 at 08:14:01 UT (about 4.06 hr after the trigger) and we obtained 3x200 s exposures in the Pan-STARRS z filter. In the stacked image, we do not detect any new source within the Swift/XRT source #2 error circle (Bernardini et al., GCN 43304) and at the position of the SVOM/VT optical counterpart (Wu et al., GCN 43300).

We measure the following upper limit calibrated against the Pan-STARRS DR1 catalog, and not corrected for Galactic extinction:

z > 20.1 AB (3-sigma, mid-time 4.13 hr after the trigger).

This project is funded by the SVOM collaboration.