{
  "bibcode": "2025GCN.41355....1J",
  "subject": "GRB 250813B: Ondrejov D50 fast decay",
  "submittedHow": "email",
  "circularId": 41355,
  "createdOn": 1755132418290,
  "body": "M. Jelinek, J. Strobl, F. Novotny, R. Hudec (ASU CAS Ondrejov)\nreport:\n\nFurther to our earlier report (GCN 41353), we provide refined photometric\nanalysis of the optical afterglow of GRB 250813B (Xie et al., GCN 41352).\n\nOur photometry reveals an extremely rapid decay with the afterglow fading\nfrom the initial magnitude of ~14.4 at ~100s post-trigger to near magnitude\n20 at 0.03 days (43 minutes) after the trigger. This represents a fade of\napproximately 5.6 magnitudes in less than one hour and an average decay\nrate of ~1.8.\n\nPotential observers should note the rapid evolution when planning follow-up\nobservations.\n",
  "submitter": "Martin Jelinek at Astro.Inst-AVCR,Ondrejov <martin.jelinek@asu.cas.cz>",
  "eventId": "GRB 250813B"
}