{
  "bibcode": "2018GCN.22803....1G",
  "body": "C. Guidorzi (U. Ferrara), S. Kobayashi (LJMU), C.G. Mundell (U. Bath), \nA. Gomboc (U. Nova Gorica), I.A. Steele (LJMU), A. Cucchiara (U. of \nVirgin Islands) on behalf of a large collaboration report:\n\nThe LCO 1-m unit at McDonald Observatory began observing Swift GRB \n180620A (Evans et al. GCN 22798) on June 20, 08:55 UT (20 min since the \nGRB trigger time) with the SDSS griz filters. The optical counterpart \n(Evans et al.; Butler et al. GCN 22799; Elenin et al. GCN 22800; Tyurina \net al. GCN 22801) is clearly detected in each individual frame with the \nfollowing magnitudes:\n\nMid Time since GRB��� Exposure�������� Filter������� Magnitude\n(hrs)����������������� (s)\n------------------------------------------------------------------\n0.349���������������� 1x120����������� SDSS-R������� 18.63 +- 0.04\n0.583���������������� 1x120����������� SDSS-I������� 18.27 +- 0.04\n------------------------------------------------------------------\n\nas calibrated against nearby PanSTARRS objects.",
  "circularId": 22803,
  "createdOn": 1529496116000,
  "email": "guidorzi@fe.infn.it",
  "subject": "GRB 180620A: LCO McDonald observations",
  "submitter": "Cristiano Guidorzi at Ferrara U,Italy  <guidorzi@fe.infn.it>",
  "eventId": "GRB 180620A"
}