TITLE: GCN CIRCULAR NUMBER: 22215 SUBJECT: GRB 171205A: UKIRT near-IR observations DATE: 17/12/09 18:18:33 GMT FROM: Tanmoy Laskar at UC Berkeley T. Laskar (NRAO / UC Berkeley), W.Fong (Northwestern University), P. Milne, and N. Smith (University of Arizona) report: "We observed GRB 171205A (D'Elia et al., GCN 22177) with the Wide Field Camera (WFCAM) mounted on the 3.8-m United Kingdom Infrared Telescope (UKIRT) on Mauna Kea beginning on 2017 December 8.595 UT (3.29 days post-burst) in the J- and K-bands. Using the quick-look pipeline ORAC-DR, we clearly detect the near-IR counterpart, consistent with the XRT and optical position (Osborne et al.; GCN 22179, Izzo et al.; GCN 22180, Emery et al.; GCN 22181). We estimate the following preliminary photometry at the position of the near-IR afterglow, calibrated to 2MASS and converted to the AB system: J(AB) = 18.5 +/- 0.1 mag K(AB) = 18.3 +/- 0.1 mag We note that these magnitudes may have a non-negligible contribution from the host galaxy. Further observations are planned to track the brightness evolution and determine the galaxy contribution. We thank Watson Varricatt and Sam Benigni for their assistance in planning and executing these observations."