GCN Circular 44659

Subject

GRB 260516D: LCO optical observations

Event

GRB 260516D

Date

2026-05-17T08:22:30Z (11 days ago)

From

SVOM_group <svomgroup@bao.ac.cn>

Via

Web form

C. Wu (NAOC), A. Saccardi (CEA/Irfu), L.P. Xin (NAOC) report on behalf of the SVOM mission team:

We observed the field of the SVOM/ECLAIRs GRB 260516D (Brunet et al., GCN 44649

) with the LCO 1m telescope at McDonald Observatory and Cerro Tololo equipped with the Sinistro instrument.

Our observation started on 2026-05-17 at 06:26:56 UT (about 9.79 hr after the trigger) and we obtained 3x200 s exposures in the SDSS r and 3x200 s exposures in the Pan-STARRS z filters.

The optical counterpart (Li et al., GCN 44654

; Mohan et al., GCN ; García et al., GCN ) with redshift of 1.801 (Izzo et al., GCN ) is faintly detected in our images. We measure the following magnitudes calibrated against the Pan-STARRS DR1 catalog, and not corrected for Galactic extinction:

r = 21.75 +/- 0.10 AB (mid-time 9.88 hr after the trigger);
z > 21.2 AB (3-sigma, mid-time 10.00 hr after the trigger).

This project is funded by the SVOM collaboration.