{
  "bibcode": "2025GCN.40975....1L",
  "eventId": "EP250704a",
  "body": "W. X. Li, S. J. Xue (NAOC), M. Andrews, J. Farah, D. A. Howell, M. Newsome, E. Padilla Gonzalez, C. McCully, and G. Terreran (Las Cumbres Observatory), on behalf of a larger collaboration, report:\nFollowing the detection of the fast X-ray transient EP250704a/GRB 250704B (Li et al., GCN 40491, 40956; Wang et al., GCN 40940; Frederiks et al., GCN 40972), we initiated observations of the fast X-ray transient location starting on July 05 at 4:16 UT (~20 hours after the EP/WXT trigger) in the g, r and i bands. These observations were conducted using the 1-meter telescope at the Las Cumbres Observatory node located at the Cerro Tololo Inter-American Observatory in Chile.\nThe optical counterpart, detected by COLIBRÍ (Schneider et al., GCN 40942), VLT/FORS2 (Malesani \n et al., GCN 40945), BOOTES-5 (Pérez-García et al., GCN 40957), Pan-STARRS (Gillanders et al., GCN 40958), SVOM/VT (Xin et al., GCN 40960), GROWTH-India (Mohan et al., GCN 40962), SAO RAS (Moskvitin et al., GCN 40963), JinShan (Liu et al., GCN 40965), VLT/X-shooter (An et al., GCN 40966), VLT/HAWK-I (Yang et al., GCN 40970), and NOT (Ricci et al., GCN 40970), is clearly detected in all LCO exposures, with preliminary magnitudes of g ≈ 20.2, r ≈ 20.1, and i ≈ 20.0 (AB mag).\n\nThese observations were taken as part of the Global Supernova Project.",
  "circularId": 40975,
  "submitter": "Wenxiong Li at NAOC <liwenxiong1992@gmail.com>",
  "createdOn": 1751720163083,
  "subject": "EP250704a/GRB 250704B: GSP observations of the optical counterpart",
  "submittedHow": "web",
  "format": "text/plain"
}