GCN Circular 6456

T. Minezaki (IoA, Tokyo) and P.A. Price (IfA, Hawaii) report on behalf
of a larger collaboration:

We observed the localisation of GRB070521 with the MAGNUM telescope +
MIPS dual-beam imager.  While our observations consist of both optical
and NIR images, we report here only the NIR imaging.  We do not find any
afterglow within the XRT error circle (GCN ##6431,6452) to the following
limits (based on flux calibration with a nearby 2MASS star):

Filter		t - t_GRB (min)		Limit (mag)
J		49.2			20.7
H		106.6			20.3
K		87.1			19.2

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