{
  "subject": "GRB 221231A: AKO Upper Limit",
  "eventId": "GRB 221231A",
  "bibcode": "2023GCN.33136....1O",
  "createdOn": 1672595230000,
  "circularId": 33136,
  "submitter": "Mohammad Odeh at Al Khatim Observatory M44  <mshodeh@gmail.com>",
  "email": "mshodeh@gmail.com",
  "body": "Mohammad Odeh of Al-Khatim Observatory (AKO) operated by the International\nAstronomical Center, in Abu Dhabi, UAE. \n\n \n\nAs a follow up for the GRB 221231A detected by Fermi/GBM (GCN 33129) and the\nobservations of the Swift/BAT-GUANO (Perri et al., GCN 33135), we observed\nthe localization of the five detected uncatalogued X-ray sources mentioned\nin GCN 33135. Our observation was done with our 0.36m f/7.7 robotic\ntelescope on 01 January 2023 around 15:27 (UT), 17.7 hours after the GRB\ntrigger. We obtained multiple 180-sec exposures in Ic filter. We did not\ndetect any afterglow within the mentioned locations. \n\n \n\nThe following upper limit was calculated using Atlas catalogue as a\nreference:\n\n----------------------------------------------------------------------------\n-\n\nJD (mid), T_mid-T0(hrs), Exposure (sec), Filter, Lim_mag\n\n----------------------------------------------------------------------------\n-\n\n2459946.143993, 17.7, 5 x 180 (stacked), Ic, > 18.8\n\n----------------------------------------------------------------------------\n-\n\n \n\nThese magnitudes are not corrected for galactic extinction."
}