GCN Circular 6570

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.