{
  "bibcode": "2019GCN.23740....1I",
  "body": "Myungshin Im, Gregory S. H. Paek, Changsu Choi (CEOU/SNU), on behalf of a\nlarger collaboration\n\nWe observed the afterglow of GRB 190114C (Gropp et al., GCN 23688; Tyurina\net al., GCN 23690, de Ugarte Postigo et al., GCN 23692, Lipunov et al. GCN\n23693, Selsing et al. GCN 23695, Izzo et al. GCN 23699, Bolmer et al. GCN\n23702, Castro-Tirado et al. GCN 23708, Kann et al. GCN 23710, Im et al. GCN\n23717; Siegel et al. GCN 23725, Mazaeva et al. GCN 23727, D'Avanzo et al.\nGCN 23729, Peak et al. GCN 23731, Kim et al. GCN 23732, Kumar et al.\nGCN 23733) with the United Kingdom Infrared Telescope (UKIRT). The\nobservation started at 2019-01-16 05:06 UT or about 1.33 days after the\ninitial alert.\n\nThe afterglow is clearly detected in all J, H, K bands, and preliminary\nmagnitudes are derived from quick-look data, using nearby 2MASS stars as\nphotometry references.\n\nFilter Date UT-start Vega_Mag (AB mag)\nK   2019-01-16 05:06:05.011    15.5 +/- 0.1   (17.7 AB)\nH   2019-01-16 05:26:45.974    16.5 +/- 0.1   (18.1 AB)\nJ    2019-01-16 05:47:58.042    17.5 +/- 0.1   (18.7 AB)\n\nThis shows an H-band fading of 1.4 mag with respect to the value reported\nby D'Avanzo et al. (GCN 23729) which give an H-band fading rate of 1.2\nmag/day.\n\nFurther observations are planned.\nWe thank the staffs at UKIRT for carrying out the observation.",
  "circularId": 23740,
  "createdOn": 1547651320000,
  "email": "mim@astro.snu.ac.kr",
  "subject": "GRB 190114C: UKIRT JHK observation",
  "submitter": "Myungshin Im at Seoul Nat U  <mim@astro.snu.ac.kr>",
  "eventId": "GRB 190114C"
}