GCN Circular 34566
Subject
Swift J1727.8-1613 (GRB 230824A): GAD Observatory La Spezia - optical observations
Event
Date
2023-08-26T20:45:21Z (2 years ago)
From
Claudio Lopresti <cl3lop@gmail.com>
Via
legacy email
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; Navaneeth et al., GCN 34538, Odeh et al., GCN 34543) 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, 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.