{
  "createdOn": 1755252838230,
  "body": "Giovanni Calapai at Calapai Astronomical Observatory, Massa S. Giorgio, (Messina) Italy \nMember of: GRB/UAI Gamma Ray Burst Section of Unione Astrofili Italiani. \n\nReport:\n\nWe imaged the field of GRB 250813B detected by SVOM/ECLAIRs telescope (Xie et al. GCN 41352 - 41354), with the 11 inches Schmidt-Cassegrain (Celestron 11) telescope F/D=6,3. \n\nThe observations were started at 2025-08-14 00:02 UT (approximately 1.19 hours after burst) stacking a set of unfiltered CCD image. The observations were carried out with partially clear skies and Moon (illumination: 74%, distance: 42°). \n\nWe co-added 93 exposures of 60 sec each.\n\nStart T0+      End T0+     CR lim\n1.19 hour     4.44 hour     20.1\n\nWe did not found any optical counterpart in the error box of the XRTcandidate (Page et al. GCN 41359).\n\nMagnitudes were estimated with the PanSTARRS cat. and are not corrected for galactic dust extinction.\n\nOur observations are consistent with other already reported Jelinek et al. (GCN 41355), Gill et al. (GCN 41356), Corcoran et al. (GCN 41370).\n\nThe message may be cited.",
  "circularId": 41388,
  "submittedHow": "web",
  "subject": "GRB 250813B: Calapai Observatory, Massa S. Giorgio (Messina), upper limit",
  "eventId": "GRB 250813B",
  "bibcode": "2025GCN.41388....1C",
  "format": "text/plain",
  "submitter": "Giovanni Calapai at Calapai Astronomical Observatory, Massa S. Giorgio, Messina, Italy <giovannicalapai@tiscali.it>"
}