TITLE: GCN CIRCULAR NUMBER: 25584 SUBJECT: GRB 190829A: UKIRT detection of the NIR Afterglow DATE: 19/08/31 00:49:09 GMT FROM: Gregory SungHak Paek at SNU Gregory S. H. Paek and Myungshin Im (CEOU/SNU), on behalf of a larger collaboration We observed the afterglow of GRB 190829A (Fermi GBM Team, GCN 25551; Dichiara et al., GCN 25552) with the United Kingdom Infrared Telescope (UKIRT). The observation started at 2019-08-30 12:30:51.984 UT or about 16 hours after the event. The afterglow is clearly detected in all J, H and K bands, and preliminary magnitudes are derived from quick-look data, using nearby 2MASS stars as photometry references. Filter Date UT-start AB_mag K 2019-08-30 12:30:51.984 16.95 +/- 0.21 H 2019-08-30 12:38:40.013 17.53 +/- 0.08 J 2019-08-30 12:46:27.005 18.09 +/- 0.05 This shows an J-,H-, and K-band fading of 0.75, 0.85, and 0.55 mag with respect to the value reported by Chen et al. (GCN 25569). Further observations are planned. We thank the staffs at UKIRT for carrying out the observation. [GCN OPS NOTE(05sep19): Per author's request, the referenced Circular in the first line was changed from "2555" to "25551".]