{
  "circularId": 39477,
  "submitter": "Wenxiong Li <liwenxiong1992@gmail.com>",
  "bibcode": "2025GCN.39477....1L",
  "eventId": "EP250225a",
  "format": "text/plain",
  "createdOn": 1740547533872,
  "submittedHow": "web",
  "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 EP250225a by the Einstein Probe (Jiang et al., GCN 39475) with the Sinistro instrument mounted on the 1-m telescope of the LCO, we initiated observations of the fast X-ray transient location starting on 2025 Feb 26th at 04:50:50 UT (~15 hours after the EP/WXT trigger) in the r band. 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.\nNo new optical source was detected in the co-added images within the EP/WXT error box down to ~21.5 mag.\nThese observations were taken as part of the Global Supernova Project.",
  "subject": "EP250225a: GSP optical upper limit"
}