GCN Circular 34566

Claudio Lopresti (Gruppo Astronomia Digitale - GAD Observatory, La Spezia, Italy - UAI SSV- GRB Section)
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)
Unione Astrofili Italiani (UAI SSV- GRB Section)
report:

I imaged the field of of Swift J1727.8-1613 (GRB 230824A) (Page et al., GCN 34537
Not found
 
 
; Navaneeth et al., GCN 34538
Not found
 
 
, Odeh et al., GCN 34543
Not found
 
 
) with the following telescope: 0.18-m f/4 Mak-Newton reflector at GAD Observatory, Italy, with filters Infrared, Red, and V.  I clearly detected a bright object, in the same location as M.Odeh et al., GCN 34543
Not found
 
 
, within the uncertainty radius of the Swift localization, at: R.A. (J2000): 17:27:43.32 Dec. (J2000): -16:12:18.8.

The results of photometry are:

In Infrared band:
=============================================
         Date UT         Exp Time   I-mag    Err
=============================================
2460181.3096064800    90s    13.71    0.10
2460181.3143750000    90s    13.85    0.08
2460181.3191319400    90s    13.83    0.04
2460181.3239004600    90s    13.78    0.03
2460181.3286689800    90s    13.80    0.02
2460181.3334259200    90s    13.82    0.06
2460181.3519444400    90s    13.90    0.09
2460181.3559490700    180s    13.72    0.09
2460181.3599537000    180s    13.79    0.05
2460181.3639583300    180s    13.69    0.03
2460181.3679745300    180s    13.73    0.03
2460181.3719907400    180s    13.83    0.07
2460181.3760069400    180s    13.71    0.09


In Red band:
=============================================
        Date UT         Exp Time  R-mag   Err
=============================================
2460181.3119675900    90s    14.09    0.00
2460181.3167361100    90s    14.09    0.02
2460181.3215046200    90s    14.05    0.04
2460181.3262615700    90s    14.14    0.05
2460181.3310300900    90s    14.15    0.08
2460181.3532407400    90s    14.01    0.07
2460181.3572569400    180s    14.06    0.05
2460181.3612615700    180s    13.96    0.06
2460181.3652662000    180s    13.96    0.00
2460181.3692824000    180s    13.96    0.01
2460181.3732986100    180s    13.98    0.01


In V band:
=============================================
           Date UT        Exp Time  V-mag    Err
=============================================
2460181.3586111100    90s    13.51    0.09
2460181.3626157400    90s    13.37    0.07
2460181.3666203700    90s    13.44    0.04
2460181.3706365700    90s    13.46    0.01
2460181.3746527700    90s    13.45    0.01


Magnitudes were estimated with the PanSTARRS cat., not corrected for galactic dust extinction. Weather conditions were good.

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

The message may be cited.