GCN Circular 34430

U.Quadri and  L.Strabla (Bassano Bresciano Astronomical Observatory),

Members of: 
AAVSO - American Association of Variable Star Observers.
UAI/SSV - Unione Astrofili Italiani/sezione stelle variabili-GRB.
GAC - Gruppo Astrofili Cremonesi.

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 re-observed 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 & Spiridonova GCN 34406
Not found
 
 
; Leonini et al. GCN
34408
Not found
 
 
; de Ugarte Postigo et al. GCN 34409
Not found
 
 
; de Ugarte Postigo et al.
GCN 34410
Not found
 
 
; Belkin et al. GCN 34412
Not found
 
 
; Ruocco et al. GCN 34413
Not found
 
 
; Frederiks
et al. GCN 34414
Not found
 
 
; Ruocco et al. GCN 34415
Not found
 
 
; Shrestha et al. GCN 34416
Not found
 
 
;
Quadri et al. GCN 34417
Not found
 
 
; Adami et al. GCN 34418
Not found
 
 
; Moretti et al. GCN
34419
Not found
 
 
; Kumar et al. GCN 34420
Not found
 
 
; Belkin et al. GCN 34421
Not found
 
 
 & GCN 34423
Not found
 
 
;
Pyshna et al., GCN 34425
Not found
 
 
) with our 0.25-m Newton robotic telescope.

We coadded 155 x 60 sec. unfiltered images on August 14 2023, 
from 19:46:11 to 22:32:27 UT

We confirm a fading afterglow at the following coordinates +/- 0.2 arcsec:

RA (J2000.0) =  16h 36m 31.51s
DEC(J2000.0) = +47d 51p 32.2s

The results of OT photometry are:

-----------------------------------
      JD         mag      Err   Flt   
-----------------------------------
2460171.43558   20.5  +/- 0.3   CR    
    

CR is unfiltered with Rc zero point.

Magnitudes were estimated with the Pan-STARRS cat. 
and are converted using Lupton (2005) equations.

Not corrected for galactic dust extinction.

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

The message may be cited.