{
  "bibcode": "2026GCN.44592....1C",
  "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 observed the field of GRB 260511B detected by Fermi/GBM (Fermi GBM Team, GCN 44542) and SVOM/ECLAIRs (Godet et al., GCN 44543) with the 14 inches Schmidt-Cassegrain (Celestron 14) telescope F/D=7. \n  \nThe observations were started at 2026-05-11 21:24:23 UT (approximately 10.40 hours after burst) stacking two sets of unfiltered CCD image. The observations were carried out with clear skies and good visibility conditions.\n\nThe OT was detected at the following position:\n\nRA    (J2000.0)  12h 50m 17.18s   \nDecl. (J2000.0) +04° 03' 10.2\" \t \n\nPhotometry was obtained using nearby PanSTARRS stars as follows: \n\nObservation    Mid-Time    T-T0 (hr)      Exposure        Filter      Mag.     Mag. err.\n2026-05-11   21:54:50 UT   10.91           60x60s           CR       18.85     +/-0.04\n2026-05-11   23:01:52 UT   12.02           72x60s           CR       18.95     +/-0.04\n\nMagnitude was calibrated with the nearby PanSTARRS stars converted using Lupton (2005) equations. \nNo correction for galactic dust extinction was applied.\n\nOur observations are consistent with other already reported Wu et al. (GCN 44547); Sasada et al. (GCN 44549); Jiang et al. (GCN 44551); Wu et al. (GCN 44552); Li et al. (GCN 44557); Vijaykumar et al. (GCN 44561); De Ugarte Postigo et al. (GCN 44565); Lee et al. (GCN 44567); Li et al. (44568); Belkin et al. (GCN 44572); Saccardi et al. (GCN 44574); Rajabov et al. (GCN 44576); Pérez-Fournon et al. (GCN 44577); Novotný et al. (GCN 44580); Moskvitin (GCN 44582).\n\nThe message may be cited.",
  "subject": " GRB 260511B: Calapai Observatory, Massa S. Giorgio (Messina), optical observation.",
  "createdOn": 1778631854210,
  "format": "text/plain",
  "submittedHow": "web",
  "circularId": 44592,
  "eventId": "GRB 260511B",
  "submitter": "Giovanni Calapai at Calapai Astronomical Observatory, Massa S. Giorgio, Messina, Italy <giovannicalapai@tiscali.it>"
}