GCN 43509: GRB 260114A: SVOM/VT optical upper limits

2026-01-25T04:16:37.109Z | rev 0 | event: GRB 260114A
Y. N. Ma (NAOC), R. Z. Li (YNAO), L. P. Xin, H. L. Li, Z. H. Yao, Y. L. Qiu, C. Wu, X. H. Han, Y. Xu, J. Wang, P. P. Zhang, W. J. Xie, Y. J. Xiao, H. B. Cai, L. Lan, J. S. Deng, J. Y. Wei, D. H. Zhao (NAOC), J. Palmerio (CEA), B. T. Wang (YNAO), Y. H. Cheng (YNU) report on behalf of the SVOM/VT team. 

SVOM/VT performed a Target of Opportunity observation of GRB 260114A detected by Swift/BAT, Fermi/GBM, SVOM/GRM, GECAM-B, Konus-Wind and Insight-HXMT/HE (Fermi GBM Team, GCN 43395; Eyles-Ferris et al., GCN 43396; Bissaldi, GCN 43400; Ren et al., GCN 43402; Wang et al., GCN 43404; Beardmore et al., GCN 43412; Ridnaia et al., GCN 43413; Ren et al., GCN 43503). SVOM/VT began observing the field at 2026-01-14 14:47:02 UTC, 3.11 hours after T0, in the VT_B (400nm-650nm) and VT_R (650nm-1000nm) channels simultaneously. 

We performed the second observation as a template on January 19th. After performing image subtraction of our stacked images against the second observation, no uncataloged candidate was detected within the error box provided by Swift/XRT position (Beardmore et al., GCN 43412) or the optical counterpart previously reported by GMG (Li et al., GCN Circ. 43398) and the Mondy observatory (Volnova et al., GCN Circ. 43401). The three sigma limits are: 

mid-time  | exposure time   | band  | upper limit (AB) 
----------|-----------------|-------|----------------- 
4.241 h   |  69*70 sec      | VT_B  | > 23.8 mag
4.251 h   |  67*70 sec      | VT_R  | > 23.5 mag

Our results are consistent with MASTER (Lipunov et al., GCN Circ. 43403), NOT (Corcoran et al., GCN Circ. 43406), TNG (Brivio et al., GCN Circ. 43407), COLIBRÍ (Angulo et al., GCN 43408), MITSuME (Takahashi et al., GCN 43409), VLT (Yang et al., GCN 43414; Schneider et al ., GCN 43423) and Swift/UVOT (Siegel & Eyles-Ferris, GCN 43473).

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.