GCN Circular 34488
Subject
GRB 230818A: Bassano Bresciano Observatory optical observations
Event
Date
2023-08-19T14:56:53Z (2 years ago)
From
Ulisse Quadri at Bassano Bresciano Obs <oabb@ulisse.bs.it>
Via
legacy email
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.
We imaged the field of GRB 230818A detected by SWIFT(trigger 1186032)
with the robotic telescope of (IAU station 565) Bassano Bresciano
Observatory, Italy.
The observations started 13.61 min after the GRB trigger,
with our Newton automated telescope D=250 mm F/D=4.8.
Weather conditions were good.
We co-added 3 series of 10 exposures of 60 sec each.
We detected afterglow in the error box of the XRTcandidate.
(Fermi GBM team, GCN 34478; Tohuvavohu et al., GCN 34479;
Ben Gompertz et al., GCN 34480; V. Lipunov et al. GCN 34482;
A. S. Moskvitin et al., GCN 34483; D.B. Malesani et al., GCN 34485;
N. Pankov et al., GCN 34487) at the following position (+/- 2 arcsec):
RA (J2000.0) = 19 03 33.21
DEC(J2000.0) = +40 53 49.5
Our photometry of the afterglow are:
Date U.T. R mag Sigma
------------------------------------
2023 08 18.99405 18.90 0.07
2023 08 19.00126 19.21 0.07
2023 08 19.00154 19.47 0.06
----------------------------------
COMPARISON STARS
--------------------------------------------------------------------
pan-STARRS ID g r i Rc
--------------------------------------------------------------------
157072858562487290 17.4025 16.7800 16.5376 16.56
157052858895609613 16.8323 16.3279 16.1482 16.13
157072859081709765 15.0561 14.7054 14.5820 14.53
157092859169446573 16.9397 16.4745 16.2972 16.28
157102858906415897 17.0217 16.4894 16.2798 16.28
157062859601321798 15.7561 15.2872 15.0934 15.09
--------------------------------------------------------------------
Magnitudes were estimated with the Pan-STARRS cat.
Rc mag are derived using Lupton (2005) equations.
Not corrected for galactic dust extinction.
Reference:
http://www.osservatoriobassano.org/GRB.asp
The message may be cited.