{
  "subject": "GRB 190114C: Continued UKIRT JHK observation",
  "eventId": "GRB 190114C",
  "bibcode": "2019GCN.23747....1I",
  "createdOn": 1547735759000,
  "circularId": 23747,
  "submitter": "Myungshin Im at Seoul Nat U  <mim@astro.snu.ac.kr>",
  "email": "mim@astro.snu.ac.kr",
  "body": "Myungshin Im, Gregory S. H. Paek, Changsu Choi (CEOU/SNU), on behalf of a\nlarger collaboration\n\nWe observed again the afterglow of GRB 190114C (Gropp et al., GCN 23688;\nTyurina et al., GCN 23690, de Ugarte Postigo et al., GCN 23692, Lipunov et\nal. GCN 23693, Selsing et al. GCN 23695, Izzo et al. GCN 23699, Bolmer et\nal. GCN 23702, Castro-Tirado et al. GCN 23708, Kann et al. GCN 23710, Im et\nal. GCN 23717, 23741; Siegel et al. GCN 23725, Mazaeva et al. GCN 23727,\nD'Avanzo et al. GCN 23729, Peak et al. GCN 23731, Kim et al. GCN 23732,\nKumar et al. GCN 23733, Mazaeva et al. GCN 23741, 23746, Kumar et al. GCN\n23742) with the United Kingdom Infrared Telescope (UKIRT). The observation\nstarted at 2019-01-17 05:06 UT or about 2.33 days after the initial alert.\n\nPreliminary magnitudes are derived from quick-look data, using nearby 2MASS\nstars as photometry references. The afterglow faded by about 0.5 magnitude\nin all of the JHK bands with the J-band magnitude given below.\n\nFilter Date UT-start Vega_Mag (AB mag)\nJ    2019-01-16 05:47:58.042    18.0 +/- 0.1   (19.2 AB)\n\nThe result implies that the current fading of NIR afterglow (0.5 mag/day)\nis slower  than what we reported in a previous circular (1.2 mag/day) based\non earlier data (Im et al. GCN 23740).\n\nFurther observations are planned.\nWe thank the staffs at UKIRT for carrying out the observation."
}