{
  "format": "text/markdown",
  "submittedHow": "web",
  "body": "X. Liu (NAOC), K. Noysena, K. Chanchaiworawit, S. Tinyanont (NARIT), L.B. He, Z.P. Zhu, S.Q. Jiang, J. An, D. Xu (NAOC), S.Y. Fu (HUST) report on behalf of a large collaboration:\n\nWe observed the field of GRB 250805A (Ambrosi et al, GCN 41233), using the 0.7-m telescope of the Thai Robotic Telescope network (TRT), located at Cerro Tololo Inter-American Observatory, Chile. Observations started at 06:27:50.5 UTC on 2025-08-05, i.e., ~ 0.3 hr after the Swift/BAT trigger, and 10 x 200 s frames were obtained in the Sloan r- and i- bands.\n\nNo new optical source is detected in the co-added r- and i-band images within the Swift/XRT error circle (Kennea et al, GCN 41234). The limiting magnitudes are as follow:\n\n| Tmid(s) | band | upper limit(3sigma) |\n| :-----: | :--: | :-----------------: |\n| 2746.99 |  i   |        20.7         |\n| 3545.62 |  r   |        20.8         |\n\nThe magnitudes are calibrated against Legacy Survey DR10 and are not corrected for Galactic extinction.",
  "submitter": "liuxing@nao.cas.cn",
  "createdOn": 1754384191519,
  "circularId": 41236,
  "subject": "GRB 250805A: TRT optical upper limits",
  "eventId": "GRB 250805A",
  "bibcode": "2025GCN.41236....1L"
}