{
  "bibcode": "2022GCN.32281....1G",
  "body": "P.J. Groot (Radboud/UCT/SAAO), S. de Wet (UCT/SAAO), P.M. Vreeswijk\n(Radboud) report on behalf of the MeerLICHT consortium:\n\nFollowing the detection of GRB220627A by Fermi (Fermi GBM team, GCN\n32278) the MeerLICHT 0.6m wide-field optical telescope, located at\nSAAO Sutherland, South Africa, started scanning the error box at\n2022-06-27 21:43 UT (T0+23 minutes and 3 minutes after the alert was\nreceived). Observations were obtained in the q-band (440-720nm), using\n52 tiles (146 square degrees) to cover a 71% cumulative\nprobabilty. Before the observability limit of HA=+4.5 hr was reached\n32.4 square degrees were covered at least twice, covering a cumulative\nprobability of 7.5% of the Fermi error box.\n\nAutomatic data processing using BlackBOX/ZOGY resulted in 7 new\ntransients that were observed at least twice and were detected with a\nsignificance >12 in the difference images. Five of these candidates\ncan be associated to known asteroids. \n\nThe remaining two candidates are uncataloged and are both detected\nthree times: \n\nCandidate 1 is MLTJ143615.50-360417.3,\nat RA,Dec (ICRS) 14:36:15.50, -36:04:17.3 (219.06459,-36.07149),\nfirst detected at q_AB = 18.13+/-0.03 on 2022-06-27 22:50:22/05 (MJD\n59757.95164). Last non-detection was on MJD 58971.02.19 at q_AB > 20.35\n(for a transient source).  \n\nCandidate 2 is MLTJ143614.90-373629.0,\nat RA,Dec (ICRS) 14:36:14.90. -37:36:29.0 (219.06217,-37.60809),\nfirst detected at q_AB = 19.62+/-0.10, on 2022-06-27 22:53:20.54 (MJD\n59757.95371). Last non-detection was on MJD 59737.8835 at q_AB > 20.82\n\nCandidate 1 shows the presence of an underlying object in the MeerLICHT\nreference image at q_AB = 20.72, possibly a host galaxy. \nCandidate 2 shows no underlying source in the MeerLICHT reference image\nwith a limiting magnitude of q_AB > 20.28. \n\nDuring the three MeerLICHT observations Candidate 1 evolved to q_AB =\n18.21 +/-0.02 at 2022-06-27 23:16:51 (MJD 59757.97004). Candidate 2\nbrightened to q_AB = 19.43 +/- 0.10 at 2022-06-27 23:18:14 (MJD\n59757.97100).\n\nFollow-up observations of both candidates are encouraged. \n\nMeerLICHT is built and run by a consortium consisting of Radboud\nUniversity, University of Cape Town, the South African Astronomical\nObservatory, the University of Oxford, the University of Manchester and\nthe University of Amsterdam.",
  "circularId": 32281,
  "createdOn": 1656382349000,
  "email": "p.groot@astro.ru.nl",
  "subject": "GRB 220627A: MeerLICHT detection of two afterglow candidates",
  "submitter": "Paul Groot at Radboud University Nijmegen  <p.groot@astro.ru.nl>",
  "eventId": "GRB 220627A"
}