{
  "body": "S.Y. Fu, L. Lei (HUST), Z.P. Zhu, J. An, X. Liu, S.Q. Jiang, L.B. He, D. Xu (NAOC), X. Gao (Urumqi No.1 Senior High School), J.Z. Liu (XAO) report:\n\nWe observed the field of GRB 261017A detected by Fermi (Fermi GBM team, GCN 45973) and Swift (Siegel et al., GCN 45974), using the NEXT telescope located at Nanshan, Xinjiang, China. Observation started at 2026-10-17T21:45:23, i.e., 5.67 hours post-burst, and a series of r-band frames were obtained. \n\nNo uncatalogued optical transient is detected in the stacked image within the enhanced Swift-XRT error circle (Beardmore et al., GCN 45977), down to a 5-sigma limiting magnitude of r ~ 21.0, calibrated with Pan-STARRS DR2 stars in the field.\n\nWe acknowledge the excellent support from X. Gao for enabling these observations.",
  "subject": "GRB 261017A: Nanshan/NEXT optical upper limit",
  "createdOn": 1792295619500,
  "format": "text/plain",
  "submittedHow": "web",
  "circularId": 45978,
  "eventId": "GRB 261017A",
  "submitter": "syfu@nao.cas.cn",
  "eventType": [
    "GRB"
  ]
}