GCN Circular 34445

Claudio Lopresti (Gruppo Astronomia Digitale - GAD Observatory, La Spezia, Italy),
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:

I imaged the field of GRB 230812B (Lesage et al., GCN 34387
Not found
 
 
;
Scotton et al., GCN 34392
Not found
 
 
; Page, GCN 34394
Not found
 
 
; Zheng & Filippenko, GCN 34395
Not found
 
 
;
Lipunov et al., GCN 34396
Not found
 
 
; Salgundi et al., GCN 34397
Not found
 
 
; Ackley et al., GCN 34398
Not found
 
 
;
Xiong et al., GCN 34401
Not found
 
 
; Casentini et al., GCN 34002
Not found
 
 
; Frederiks et al., GCN 34403
Not found
 
 
;
Mao et al., GCN 34404
Not found
 
 
; Odeh et al., GCN 34405
Not found
 
 
; Moskvitin et al., GCN 34406
Not found
 
 
)
detected by FERMI(trigger 713559497.049606 / 230812790)
with the GAD Observatory, La Spezia, Italy Italy.

Member of:
UAI/SSV - Unione Astrofili Italiani/sezione stelle variabili, GRB section
GAD - Gruppo Astronomia Digitale

The observations started 48.02 hour after the FERMI trigger, At the end of twilight
with a Maksutov-Newton telescope D=180 mm F/D=4

Weather conditions were good.

We co-added  series of 8 exposures of 60 sec each.

Start T0+        End T0+          R lim
3168 min       3178 min         19.6

I did not detect any optical afterglow in the Swift/XRT (Page, GCN
Circ. 34387
Not found
 
 
) position. The magnitude limit is about 19.5 mag, compared
to the magnitudes of nearby stars from the Gaia EDR3 Catalog

Magnitudes were estimated with the Gaia EDR3 cat. and
are not corrected for galactic dust extinction.

Reference:
https://www.parcodellestelle.com/

The message may be cited.