{
  "bibcode": "2025GCN.39812....1P",
  "format": "text/plain",
  "submittedHow": "web",
  "createdOn": 1742561922966,
  "submitter": "Ismael Perez-Fournon at Instituto de Astrofisica de Canarias <ipf@iac.es>",
  "body": "I. Pérez-Fournon, F. Poidevin (IAC and ULL), D. Cano-Morales, I. Correa-Plasencia, A.E. Hernández-Díaz (ULL), D. Aguado, A. López-Oramas, D. Nespral (IAC and ULL), N.C. Sun (UCAS), W. Li, Y. Wang, and Z. Niu (NAOC)\n\n\nWe report Las Cumbres Observatory Global Telescope network (LCOGT) observations of EP250321a detected \nby EP/WXT (Hu et al., GCN circ. 39800), and Swift-XRT (Page et al., GCN circ. 39811). \n\nWe observed the field of EP250321a with one of the two LCOGT 1-m telescopes, equipped with Sinistro cameras, located at the LCOGT node at McDonald Observatory (Texas). We obtained a 200-sec exposure in the SDSS i' filter starting at 2025-03-21 09:38:42 UT, about 3.48 hr after the EP trigger. \n\nAn uncatalogued source is detected at the position of the optical and near-IR counterpart reported \nby Fu et al. (GCN circ. 39804), Perez-Garcia et al. (GCN circ. 39805), Brivio et al. (GCN circ. 39807), Zhu et al. (GCN circ. 39809), and Becerra et al. (GCN circ. 39810). \nZhu et al. (GCN circ. 39809) have reported a redshift of z = 4.368.\n\n\nWe measure the following magnitude, calibrated against Pan-STARRS DR2 stars and not corrected for Galactic extinction:\n\nDate      |  UT start | mag | error | filter |\n----------------------------------------------\n2025-03-21   09:38:42   19.3  0.15     i'\n\nThis work makes use of observations from the Las Cumbres Observatory global telescope network (LCOGT observing programme IAC2025A-009, SGLF).\n\n ",
  "eventId": "EP250321a",
  "circularId": 39812,
  "subject": "EP250321a: LCO optical counterpart detection"
}