TITLE: GCN CIRCULAR NUMBER: 30858 SUBJECT: GRB210919A: Keck NIRC2 Kp band upper limits DATE: 21/09/21 06:58:23 GMT FROM: Jielai Zhang at Swinburne U. of Tech. <jielaizhangscience@gmail.com> GRB210919A: Keck NIRC2 Kp band upper limits Jielai Zhang (Swinburne University of Technology, Swinburne), Jeff Cooke (Swinburne), Gabriela Canalizo (University of California Riverside), Sara Marlene Doan (George Mason University), Shobita Satyapal (George Mason University), Thomas Bohn (University of California Riverside), Jeffrey Mckaig (George Mason University) We carried out follow-up observations of GRB210919A (A. Tohuvanohu et al. GCNC #30846) with Keck II, using the NIRC2 instrument with the wide camera. Observations began on September 19 at 13:48:32.649 UT , ~13.3 hours after the GRB trigger. We took 6 X 107s exposures using the Kp filter. No GRB IR counterpart was found in the NIRC2 data within the XRT error area (M. R. Goad et al. GCNC #30850). No GRB IR counterpart was found in the NIRC2 data within the XRT error area (M. R. Goad et al. GCNC #30850) to an upper limit of Kp > 21.5 mag (AB, with no Galactic extinction correction).