TITLE: GCN CIRCULAR NUMBER: 8274 SUBJECT: GRB 080916C: IRSF/SIRUS NIR Observation DATE: 08/09/19 14:41:06 GMT FROM: Nobuyuki Kawai at Tokyo Tech T. Nagayama (Kyoto University) reports on behalf of the IRSF/SIRIUS team: We have imaged the field of GRB 080916C (van der Horst, GCN 8245) based on the localization by Fermi/LAT (Tajima et al, GCN 8246) in J, H, and Ks with the Simultaneous three-color InfraRed Imager for Unbiased Survey (SIRIUS) on the Nagoya-SAAO 1.4m telescope (IRSF) starting at 2:53 on September 17 UT for 50 min. The optical afterglow candidate suggested by Clemens et al. (GCN 8257, GCN 8272) was detected marginally in H and Ks bands. The preliminary magnitude was Ks= 18.6 +- 0.5.