TITLE:   GCN CIRCULAR
NUMBER:  6758
SUBJECT: GRB 070810B : Faulkes Telescope South Observations
DATE:    07/08/12 18:59:35 GMT
FROM:    Cristiano Guidorzi at INAF-OAB  <cristiano.guidorzi@brera.inaf.it>

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


On 2007 Aug 10 at 15:22:06 UT the 2-m Faulkes Telescope South
automatically observed the field of GRB 070810B (trigger 287409,
Marshall et al., GCN Circ. 6743).

In our coadded frames we do not detect anything corresponding to
XRT sources 1 or 2 (Starling et  al., GCN Circ. 6754)
down to the limiting magnitudes reported below.


Filter  Tstart(min)  Tstop(min)    Exposure(s)    M_lim
-------------------------------------------------------
    R       2.80          64.3          840         21.2
    i'      6.22          54.9          520         21.5
-------------------------------------------------------

Magnitudes are calibrated with respect to USNOB1 R2 in the R filter.
For the SDSS-i' filter we calibrated with the i' magnitudes derived for
USNOB1 field stars by converting from the (R2,I) magnitudes.