{
  "body": "M. H. Zhang, H. Sun (NAO, CAS), Y. J. Zhang (THU), W. Yuan (NAO, CAS) on behalf of the Einstein Probe (EP) team:\n\nEP-FXT performed a follow-up observation of GRB 250507A at 2025-05-07T07:33:50 (UTC), about 1 hour after the SVOM/ECLAIRs trigger (Wang et al., GCN # 40374). \nAn uncatalogued X-ray source (EPF_J121215.7−233519) was detected within the ECLAIRs error circle, and is potentially associated with GRB 250507A.\n\nPreliminary analysis of this source was automatically conducted, with the following results:\nRA (J2000): 183.0647 deg\nDec (J2000): -23.5883 deg\nFlux: 4.91 x 10^-13 erg/cm^2/s (observed, 0.5-10 keV)\nFlux_error: 1.54 x 10^-13 erg/cm^2/s (1 sigma)\n\nThe position uncertainty of the above source is about 10 arcsec in radius (90% C.L. statistical and systematic). \n\nWe note that this source is spacially consistent with the one reported by SVOM/MXT (Maggi et al., GCN # 40381). The flux measured by EP-FXT shows a rapid decline of more than two orders of magnitude compared to the MXT measurements over a timescale of approximately 50 minutes, consistent with the rapid decay reported previously.\n\n\nLaunched on January 9, 2024, EP is a space X-ray observatory to monitor the soft X-ray sky with X-ray follow-up capability (Yuan et al. 2022, Handbook of X-ray and Gamma-ray Astrophysics). ",
  "eventId": "GRB 250507A",
  "subject": "GRB 250507A: follow-up observation with EP-FXT",
  "createdOn": 1746632649858,
  "circularId": 40385,
  "submittedHow": "web",
  "format": "text/plain",
  "submitter": "EP Team at NAOC/CAS <ep_ta@bao.ac.cn>",
  "bibcode": "2025GCN.40385....1Z"
}