{
  "submittedHow": "web",
  "eventId": "EP240426b",
  "subject": "EP240426b: AST3-2 optical upper limit ",
  "createdOn": 1714236884044,
  "circularId": 36335,
  "bibcode": "2024GCN.36335....1S",
  "submitter": "Tianrui Sun at Purple Mountain Obs,CAS <trsun@pmo.ac.cn>",
  "body": "Tian-Rui Sun, Yan-Long Hua, Jin-Jun Geng, Xue-Feng Wu, Ke-Lai Meng (Purple Mountain Observatory, CAS), Xiao-Yan Li, Zheng-Yang Li, Yun Li, Xiang-Yan Yuan (Nanjing Institute of Astronomical Optics & Technology, CAS), Lifan Wang (TAMU), Xiao-Feng Wang, Mao-Kai Hu (Tsinghua University), Lei Hu (CMU) report on behalf the AST3 Team:\n\nFollowing the detection of EP240426b by Wide-field X-ray Telescope (WXT) on board the Einstein Probe (EP) (Pan et al. GCN 36330),\nwe use Antarctic Survey Telescope 3-2 at Dome A, Antarctic (Latitude -80.4173, Longitude 77.0950) for follow-up.\nOur observation started on 2024-04-27T12:44:01. \nNo obvious optical source was detected with an uncertainty of 3 arcmin in radius.\nOur detection limit on the coadded images is down to 19.2 mag for total 36x60s with filter i.\nWe use the ATLASREFCAT2 (Tonry et al. 2018) as the magnitude calibration reference.\n\nWe thank Prof. Michael Ashley (UNSW) for his excellent support on the operation of AST3-2."
}