{
  "bibcode": "2018GCN.23069....1S",
  "body": "D.Steeghs, J.Lyman (U. Warwick), G.Ramsay (Armagh O.), M.Dyer\n(U. Sheffield), K.Ulaczyk, A.Levan, R.Cutter (U. Warwick)\nK. Ackley, D.Galloway, E.Rol (Monash U.), V.Dhillon (U. Sheffield),\nP.O'Brien, R.Starling (U. Leicester), S.Poshyachinda (NARIT),\nD.Pollacco (U. Warwick), E.Thrane (Monash U.)\n\nreport on behalf of the GOTO collaboration:\n\nIn response to the short-duration GRB 180728B (GCN 23056, 23057, 23060),\nthe Gravitational-wave Optical Transient Observer (GOTO) observed the\nIPN triangulation region as reported in Svinkin et al. (GCN 23056).\n\nObservations were spread over four telescope array pointings,\nbeginning 2018-07-29T21:24 UT (24.25 hours after the burst) and employ\nsets of 3x120s exposures in our wide L filter(400-700nm). These fields\nwere repeated on 2018-07-30 to permit difference imaging analysis.\nConditions were affected by dust, typically achieved a 5 sigma limiting\nmagnitude of V=19.8-20.1 on 2018-07-29 and V=20.4-20.6 on 2018-07-30.\n\nWe made use of the GLADE galaxy catalog to pay particular attention to\npossible source candidates near galaxies within 200 Mpc. We find no\nsignificant sources that could be credibly associated with the GRB.\n\nFurthermore, we see no evidence for a source at the position reported\nin Lipunov et al. (GCN 23065), noting that our observations started\n4.7 hours later than the MASTER observations and thus the source\nmay have faded below our detection limit by then.\n\n\nGOTO is operated at the La Palma observing facilities of the University\nof Warwick on behalf of a consortium including the University of\nWarwick, Monash University, Armagh Observatory, the University of\nLeicester, the University of Sheffield, the National Astronomical\nResearch Institute of Thailand (NARIT) and the Instituto de Astrofisica\nde Canarias (IAC)\n\nhttps://goto-observatory.org/",
  "circularId": 23069,
  "createdOn": 1533074174000,
  "email": "D.T.H.Steeghs@warwick.ac.uk",
  "subject": "GRB 180728B: GOTO optical search over IPN region",
  "submitter": "Danny Steeghs at U.of Warwick/GOTO  <D.T.H.Steeghs@warwick.ac.uk>",
  "eventId": "GRB 180728B"
}