TITLE: GCN CIRCULAR NUMBER: 6570 SUBJECT: WHT observations of GRB070621 DATE: 07/06/22 12:33:06 GMT FROM: Evert Rol at U.Leicester N. Tanvir, E. Rol (University of Leicester) and A. Cardwell (ING), report on behalf of a larger collaboration: We observed the position of GRB070621 (Sbarufatti, GCNC 6560) with the Auxiliary Port Instrument on the William Herschel Telescope at La Palma, for 25 minutes starting at 4:14 UT, June 22 (average time 5.17 hours after burst). We detect the extended object mentioned by Malesani et al. (GCNC 6565), at a magnitude of I = 21.21 +/- 0.05. We also detect the source on the east edge of the refined XRT error circle (Sbarufatti, GCNC 6569) mentioned by Bloom et al (GCNC 6568), with a magnitude of I = 22.5 +/- 0.1. Photometry was performed relative to the USNO star 0651-0871887, which has an I2 magnitude of 17.21.