TITLE: GCN GRB OBSERVATION REPORT NUMBER: 2652 SUBJECT: Triangulation of GRB 040816 (Konus-Wind - Helicon-Coronas-F) DATE: 04/08/19 13:41:45 GMT FROM: Dmitry Frederiks at Ioffe Institute S. Golenetskii, E. Mazets, V. Pal'shin, and D. Frederiks on behalf of Konus-Wind and Helicon/Coronas-F teams, T. Cline, on behalf of the Konus GRB team, GRB 040816 was detected by Konus-Wind at 08:19:58.724 UT and Helicon-Coronas-F at 08:19:53.763 UT. It consisted of hard short initial peak with a duration of approximately 0.78 s, and a much less intense and softer peak ~24.5 s after the trigger time with a tail lasting for approximately 30 s. The peaks were detected by both instruments and had the same relative time delay, so we suppose that they had the same origin. We have triangulated it to a preliminary annulus: RA(2000) = 311.825 deg, Decl(2000) = -20.528 deg, Radius = 27.353 +/- 1.079 degrees (3 sigma ).