TITLE:   GCN CIRCULAR
NUMBER:  6645
SUBJECT: GRB 070721A : Faulkes Telescope South optical limit
DATE:    07/07/21 15:25:42 GMT
FROM:    Andrea Melandri at Liverpool John Moores U  <axm@astro.livjm.ac.uk>

A. Melandri, (Liverpool JMU), C. Guidorzi (Uni-Bicocca/INAF-OAB),
I.A. Steele, C.G. Mundell, D. Carter, R.J. Smith, C.J. Mottram,
D.F. Bersier, S. Kobayashi, M.J. Burgdorf, M.F. Bode (Liverpool JMU),
A. Gomboc (Ljubljana), P. O'Brien, E. Rol, N. Bannister (Leicester)
report


On 2007 Jul 21 at 13:47:14 UT the Faulkes Telescope South
observed the field of GRB070721A (trigger=285653, Ziaeepour
et al., GCN 6639).

No new source is detected inside the refined XRT error circle
(Evans et al., GCN 6644) and we can set an upper limit of
R > 20.0 between 3.9 and 4.8 hours after the trigger.