TITLE:   GCN CIRCULAR
NUMBER:  20332
SUBJECT: GRB 161219B: UKIRT near-IR afterglow detection
DATE:    16/12/22 23:40:43 GMT
FROM:    Wen-fai Fong at U of Arizona  <wfong@email.arizona.edu>

W. Fong and P. Milne (University of Arizona) report:

"We observed the field of the long-duration GRB 161219B (D'Ai et al., GCN
20296) with the Wide Field Camera (WFCAM) mounted on the 3.8-m United
Kingdom Infrared Telescope (UKIRT) on Mauna Kea beginning on 2016 Dec
22.368 UT (2.58 days post-burst). We obtained observations in the J-, H-
and K-bands in 0.72" seeing. Using the quick-look pipeline ORAC-DR, we
detect the near-IR afterglow in coincidence with the X-ray (Beardmore et
al., GCN 20297), optical (Kruehler et al., GCN 20299; Guidorzi et al., GCN
20300; Martin-Carrillo et al., GCN 20305; Marshall et al., GCN 20306;
Mazaeva et al., GCN 20309; Buckley et al., GCN 20322), and radio (Alexander
et al., GCN 20313; Laskar et al., GCN 20328) afterglows. Calibrated to
2MASS, we estimate a preliminary brightness of J(AB)=18.8 +/- 0.1 mag for
the near-IR afterglow of GRB 161219B. Further observations are planned.

We thank Watson Varricatt and Sam Benigni for their assistance in planning
and executing these observations."