GCN Circular 44628
Subject
GRB 260515A: LCO optical observations
Event
Date
2026-05-16T00:11:51Z (13 days ago)
From
SVOM_group <svomgroup@bao.ac.cn>
Via
Web form
C. Wu (NAOC), A. Saccardi (CEA/Irfu), D. B. Malesani (DAWN/NBI and Radboud), report on behalf of the SVOM mission team:
We observed the field of the SVOM/ECLAIRs GRB 260515A (Brunet et al., GCN 44622) with the LCO 1m telescope at Teide Observatory equipped with the Sinistro instrument.
Our observation started on 2026-05-15 at 22:42:33 UT (about 3.57 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 (He et al., GCN 44623; Saccardi et al., GCN 44624; Sosnovskij et al., GCN 44625; He et al., GCN 44626) is faintly detected in our images. We measure the following magnitudes calibrated against the Pan-STARRS catalog, and not corrected for Galactic extinction:
r = 21.22 +/- 0.09 AB (mid-time 4.44 hr after the trigger);
z > 20.5 AB (3-sigma, mid-time 3.63 hr after the trigger).
A marginal detection is recovered through forced photometry in the z band as well, to the level of z = 20.6 +/- 0.4 AB.
This project is funded by the SVOM collaboration.