TITLE:   GCN CIRCULAR
NUMBER:  6334
SUBJECT: GRB 070420: Faulkes Telescope South Observations
DATE:    07/04/20 14:02:57 GMT
FROM:    Cristiano Guidorzi at INAF-OAB  <cristiano.guidorzi@brera.inaf.it>

C. Guidorzi (Uni-Bicocca/INAF-OAB), R.J. Smith, D.F. Bersier, I.A. Steele,
C.G. Mundell, S.N. Fraser, C.J. Mottram, A. Melandri,
M.F. Bode (Liverpool JMU), A. Gomboc (Ljubljana), P. O'Brien,
E. Rol, N. Tanvir (U. Leicester) report on behalf of the RoboNet
GRB collaboration:

"The 2-m Faulkes Telescope South (Australia) started observing the field of
the Swift burst GRB 070420 (Stamatikos et al. GCN Circ. 6330) about 3 hours
after the trigger time in BVRi filters.

We detect the UVOT optical transient reported by Stamatikos et al
(GCN Circ. 6330) and confirmed in IR by REM (D'Avanzo et al., GCN Circ. 
6331)
in V, R and i' band filters at the following position:

RA(J2000) = 08:04:55.18
Dec(J2000)= -45:33:20.0

with an error of 0.7", and 1.2" away from the UVOT position.


Start Time   End Time    Exposure  Filter   Mag
(min)        (min)         (s)
--------------------------------------------------------
175.5        185.9        4x150      R      19.7 ± 0.4
211.3        221.8        4x150      i'     19.3 ± 0.5
--------------------------------------------------------

Magnitudes are calibrated with respect to USNOB1 R2 and I magnitudes.
Further observations are ongoing."