TITLE:   GCN CIRCULAR
NUMBER:  45566
SUBJECT: GRB 260914A: SVOM/VT optical counterpart confirmation
DATE:    26/09/14 15:09:09 GMT
FROM:    Huali Li at at NAOC, SVOM <lhl@nao.cas.cn>

H. L. Li, Y. N. Ma, C. Wu, L. P. Xin, Y. L. Qiu, Z. H. Yao, J. R. Xu, L. S. Chen, X. H. Han, J. Wang, Y. Xu, P. P. Zhang, W. J. Xie, Y. J. Xiao, H. B. Cai, J. S. Deng, J. Y. Wei (NAOC), J. T. Palmerio (CEA/Irfu)  report on behalf of the SVOM/VT team.

SVOM/VT performed observations with automatic slew of GRB 260914A detected by SVOM/ECLAIRs (sb26091401, Wang et al., GCN 45562).  Our observation started on 2026-09-14T12:04:35 UTC (about 50.5 minutes after the trigger) in the VT_B (400-650 nm) and VT_R (650-1000 nm) channels simultaneously .

With the VT X-band telemetry data, the optical counterpart (Akl et al., GCN 45564; Palmerio et al., GCN 45565) was detected in both single and stacked images.

The following measurements are in the AB magnitude and are not corrected for Galactic extinction:

Mid time | Band | Exposure Time | Brightness
0.92 hr    VT_B    7*50 s        20.48 +/- 0.11 mag
0.93 hr    VT_R    5*50 s        20.05 +/- 0.11 mag

The Space Variable Objects Monitor (SVOM) is a China-France joint mission led by the Chinese National Space Administration (CNSA, China), National Center for Space Studies (CNES, France) and the Chinese Academy of Sciences (CAS, China), which is dedicated to observing gamma-ray bursts and other transient phenomena in the energetic universe. VT was jointly developed by Xi'an Institute of Optics and Precision Mechanics (XIOPM), CAS and National astronomical observatories (NAOC), CAS.