TITLE:   GCN CIRCULAR
NUMBER:  34250
SUBJECT: GRB 230723B: Bassano Bresciano Observatory upper limit
DATE:    23/07/24 15:54:42 GMT
FROM:    Ulisse Quadri at Bassano Bresciano Obs <oabb@ulisse.bs.it>

U.Quadri and  L.Strabla (Bassano Bresciano Astronomical Observatory),
in a large collaboration with:
M.G. Dainotti (National Astronomical Observatory of Japan), 
Y. Niino (Tokyo University, Institute of Astronomy), 
K. Kalinowski (Aarhus University, Department of Physics and Astronomy),
B. De Simone (Universita' degli Studi Di Salerno)
report: 

We imaged the field of GRB 230723B detected by SWIFT(trigger 1180410)
with the robotic telescope of (IAU station 565) Bassano Bresciano 
Observatory, Italy. Member of: 
AAVSO - American Association of Variable Star Observers.
UAI/SSV - Unione Astrofili Italiani/sezione stelle variabili.
GAC - Gruppo Astrofili Cremonesi.

The observations started 518 min after the GRB trigger, at the end of twilight, 
with our Newton telescope D=250 mm F/D=4.8.

Weather conditions were medium.

We co-added 70 exposures of 120 sec each.

Start T0+      End T0+       R lim
518.43 min   598.40 min      19

We did not found any optical counterpart in the error box of the XRTcandidate.
Page et al. GCN 34234

Magnitudes were estimated with the Gaia DR2 cat. and 
are not corrected for galactic dust extinction.

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

The message may be cited.