GCN Circular 19981

U.Quadri, L.Strabla and R.Girelli report:

We imaged the field of GRB 161004A detected by SWIFT(trigger 715084)
with the robotic telescope of (IAU station 565) Bassano Bresciano 
Observatory, Italy. Member of: 
AAVSO - American Association of Variable Star Observers.
ISSP - Italian Supernovae Search Project.
UAI/SSV - Unione Astrofili Italiani/sezione stelle variabili.

The observations started 4.90 hour after the GRB trigger, at the end of twilight, 
with our Newton telescope D=250 mm F/D=4.8.

Weather conditions were good.

We co-added 3 series of 10 exposures of 60 sec each.

Start T0+      End T0+      Vlim
4.9 hour       5.5 hour        18

We did not found any optical counterpart in the error box of the XRTcandidate.
P.A. Evans (U Leicester), S. D. Barthelmy (GSFC), et al.

Magnitudes were estimated with the UCAC4 cat. and 
are not corrected for galactic dust extinction.

Reference:
http://www.osservatoriobassano.org/GRB.asp

The message may be cited.