{
  "bibcode": "2022GCN.32906....1K",
  "body": "N. Kochiashvili (AbAO), Z. Vidadi (ShAO), D. A. Kann (Goethe Univ.),\nP. Gokuldass (Florida Tech.), S. Beradze (AbAO), Sh. Aghayeva (ShAO),\nR. Le Montagner (IJCLab), C. Rinner, Z. Benkhaldoun (OUCA), A.Janati\n(HAO), S. Antier (OCA/Artemis), J. Ali, A. Kaeouach (KNC), and Sergey\nKarpov (FZU) report on behalf of the GRANDMA collaboration:\n\nThe GRANDMA telescope network responded to the Swift-BAT alert of\nGRB 221028A (Lien et al., GCN 32874, Palmer et al., GCN 32893,\nD'Elia et al., GCN 32899), which was also detected by AGILE (Ursi\net al., GCN 32885) and VZLUSAT-2 (Ripa et al., GCN 32904).\n\nThe first observations started 5.43 hours after the BAT trigger time.\nThe optical counterpart of the afterglow was not detected in our\nobservations.\n\nIn the following table we report the preliminary photometry of our\nobservations. Upper limits are reported at the 5-sigma limit,\nin the AB system.\n\nT-T0 (hr)| MJD       | Obser.   |Exposure    | Filter| Upp.Lim. (AB)\n--------------------------------------------------------------------\n5.4341   |59880.77951| MOSS     | 60 x 60 s  | Clear | 21.5\n5.8778   |59880.79591| KNC-HAO  | 47 x 180 s |   L   | 22.0\n\nMOSS data has been calibrated with the Gaia DR2 catalog.\nHAO data has been calibrated with PS1 catalog.\nValues are not corrected for the very large Galactic extinction\nE(B-V) = 1.8573 mag (Schlafly & Finkbeiner 2011).\n\nOur upper limits are in agreement with other non-detections from\nSwift UVOT (Lien et al., GCN 32874), GIT (Kumar et al., GCN 32876),\nBOOTES-4/MET (Hu et al., GCN 32878), MASTER (Lipunov et al., GCN 32879),\nLCOGT (Strausbaugh et al., GCN 32881), MITSuME (Niwano et al., GCN \n32883),\nHCT (Kumar et al., GCN 32886), COATLI (Watson et al., GCN 32888),\nZTSh 2.6m (Belkin et al., GCN 32889), AKO (Odeh et al., GCN 32894),\nNUTTelA-TAO/BSTI (Komesh et al., GCN 32896, 32897), and DFOT (Kumar et\nal., GCN 32898).\n\nGRANDMA is a worldwide coordinated telescope network\n(grandma.ijclab.in2p3.fr)  devoted to the observation of transients\nin the context of multi-messenger astrophysics (Antier et al. 2020 MNRAS\n497, 5518). Kilonova-Catcher (KNC) is the citizen science program of\nGRANDMA (http://kilonovacatcher.in2p3.fr/).",
  "circularId": 32906,
  "createdOn": 1667487319000,
  "email": "kann@iaa.es",
  "subject": "GRB 221028A: GRANDMA observations",
  "submitter": "Alexander Kann at IAA-CSIC  <kann@iaa.es>",
  "eventId": "GRB 221028A"
}