{
  "circularId": 45642,
  "submittedHow": "web",
  "body": "H. L. Li,  Y. N. Ma, C. Wu, L. P. Xin, Y. L. Qiu, Z. H. Yao, J. R. Xu, L. J. 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.\n\nSVOM/VT performed ToO observation on the field of EP260917a (Huang et al., GCN 45621). The observation started at 2026-09-18T03:23:30 UTC, 17.8 hours after trigger in VT_B (400nm-650nm) and VT_R (650nm-1000nm) channels simultaneously.\n \nNo credible uncatalogued candidates were identified in our stacked images within the error box of EP-WXT (Huang et al., GCN 45621) compared to the Legacy Survey. \n\nThe following measurements are in the AB magnitude and are not corrected for Galactic extinction:\n\nMid time | Band | Exposure Time |  5-sigma upper limit\n18.0  hr    VT_B     23*50  sec     > 22.8 mag    \n18.0  hr    VT_R     23*50  sec     > 22.7 mag\n \nOur results are consistent with the non-detections from COLIBRÍ (Guelfand et al., GCN 45624) and WINTER (Mohan et al., GCN 45628).\n\nThe 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.",
  "eventType": [
    "X-ray Transient",
    "Optical Transient"
  ],
  "subject": "EP260917a: SVOM/VT optical upper limits",
  "eventId": "EP260917a",
  "submitter": "Huali Li at at NAOC, SVOM <lhl@nao.cas.cn>",
  "format": "text/plain",
  "createdOn": 1789808582919
}