{
  "createdOn": 1714064490999,
  "submittedHow": "email-legacy",
  "circularId": 36307,
  "submitter": "Paul Groot at Radboud University Nijmegen <p.groot@astro.ru.nl>",
  "bibcode": "2024GCN.36307....1G",
  "body": "P.J. Groot (Radboud, UCT, SAAO), H. Tranin (Barcelona), H. Wichern\n(DTU), G. Leloudas (DTU), F. Stoppa (Radboud), I. Arcavi (Tel Aviv),\nS. Bloemen (Radboud), P.M. Vreeswijk (Radboud), D. Pieterse (Radboud)\nreport on behalf of the BlackGEM/MeerLICHT Consortium:\n\nFollowing the LVK Alert S240422ed the 0.6m BlackGEM/MeerLICHT\ntelescope array located at the ESO La Silla, Chile and SAAO\nSutherland, South Africa observatories observed the error box with the\nML1/BG2/BG4 telescopes using a predefined sky-grid tiling that covers\nthe accessible part of the error region using the ranked-tiling method\nas outlined in Ghosh et al. (2016). Observations were obtained in the\nq band, spanning 440-720nm, using a 2x10-tile strategy. Starting with\nthe highest probability tiles a set of 10-tiles was observed in the\nq-band filter using 60s exposures each, which was repeated directly\nafter the first 10 tiles were observed. Subsequently tiles 11-20 were\nobserved in the same two-visit manner, etc.\n\nObservations on the Updated error region of S240422ed (Biscoveanu et\nal., GCN Circular 36240) were repeated on the nights of 2024-04-23 and\n2024-04-24 following the same tiling pattern.\n\nTransient candidates were extracted using the BlackBOX/ZOGY pipeline,\nwhere astrophotometric calibrations are performed using Gaia DR3\nphotometry and astrometry. Possible asteroids are filtered using the\ndaily-updated lists of known asteroids from the Minor Planet\nCenter. All coordinates are given in the ICRS, epoch J2016.0\nastrometric frame and magnitudes quoted are on the AB system.\n\nNext to the MeerLICHT/BlackGEM detection of AT 2024hfx (Smith et al.,\nGCN36303; Groot et al., GCN36304) we find one more candidate that\ncannot be ruled out as the counterpart to S240422ed:\n\nName                   RA (ICRS) Dec(ICRS) Filter AB-Mag   Date-UT\nMLTJ080628.10-250116.4 121.61711 -25.02119 q 19.92+/-0.16 2024-04-24\n17:32:29 \n\"\"\t\t       \"\"         \"\"       q 19.70+/-0.15 2024-04-24\n17:45:43\n\nThe candidate was reported to the Transient Name Server as AT2024hgl.\n\nThe last non-detection at this position with MeerLICHT was obtained on\n2022-01-28 and is therefore not constraining. Inspection of the public\nATLAS archive shows no recent brightening or flaring at the source\nlocation.\n\n\nThe BlackGEM/MeerLICHT telescopes are designed, installed and operated\nby a consortium of the following universities and institutions:\nRadboud University, Netherlands Research School for Astronomy NOVA, KU\nLeuven, Armagh Observatory and Planetarium, Hebrew University of\nJerusalem, South African Astronomical Observatory, Technical\nUniversity of Denmark, Tel Aviv University, Texas Tech University,\nUniversity of Amsterdam, University of Barcelona, University of\nCalifornia at Davis, University of Cape Town, University of Durham,\nUniversity of Hamburg, University of Manchester, University of Oxford,\nUniversity of Potsdam, University of Valparaiso, University of\nWarwick, Weizmann Institute\n\nReferences:\nGhosh et al., 2016, A&A 592, 82\n\n",
  "subject": "S240422ed: BlackGEM/MeerLICHT transient detection AT2024hgl/MLTJ080628.10-250116.4"
}