GCN Circular 37194

Nello Ruocco at Osservatorio Nastro Verde - Sorrento (Naples) - 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: 
Following the Swift trigger no. 1247745 (GCN 37110
Not found
 
 
 P. A. Evans (U Leicester), R. A. J. Eyles-Ferris (U Leicester),K. L. Page (U Leicester) and A. Tohuvavohu (U Toronto) report on
behalf of the Neil Gehrels Swift Observatory Team) from the Swift Burst Alert Telescope (BAT), we pointed at the coordinates RA(J2000)=15h 50m 12s: Dec(J2000)=-02d 19' 15" and started our observations with telescope of Nastro Verde Observatory - Sorrento (Naples), Italy.
Member of: 
AAVSO - American Association of Variable Star Observers.
UAI/SSV - Unione Astrofili Italiani/sezione stelle variabili.


The observations started at 19:25 UT of 2023/08/09, after about 11 hours after the GRB trigger, with clear sky, with principal telescope  SC 0.35 f/10 with focal reduced + CCD Sbig ST10 XME
I took 48 unfiltered images of 60 sec . 
   Start                 End               Rlim
19:25:37 UT            20:35:28 UT         20.5

All images, calibrated with masterdark and masterflat have been measured with Thycho Tracker software
We have detected a faint source at the enhanced position reported by Swift-XRT teamat following position

RA (J2000.0)   15 50 10.54
Dec (J2000.0) -02 19 05.3  

with the following photometry and astrometry:

GRB 240809A 15 50 10.54 -02 19 05.3         20.0       C82




Magnitudes were estimated with the GAIA DR2 cat. and are not corrected for galactic dust extinction.



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