GCN Circular 34577

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. 1186959 (GCN 34537
Not found
 
 
), we pointed at the coordinates RA(J2000)=17h 27m 46s: Dec(J2000)=-16d 12' 53" 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.
AstroCampania Associazione.

The observations started at 19:23 UT of 2023/08/24, after about 5,25 hours after the GRB trigger, at the end of twilight with clear skies, with principal telescope  SC 0.35 f/10 with focal reduced + CCD Sbig ST10 XME
I took 9 image of 120 sec each in fotometric V and 13 in Rc . All images, calibrated with masterdark and masterflat have been measured with Maxim DL software
We have detected a clear visible source at the enhanced position reported by Swift Burst Alert Telescope (BAT) (Page et al., GCN 34537
Not found
 
 
 ) and by other telescopes ( Jamie A. Kennea (PSU) et al GCN 34540
Not found
 
 
., S. Dichiara (PSU) et al GCN 34542
Not found
 
 
, 34547
Not found
 
 
, 34554
Not found
 
 
,34555
Not found
 
 
., Mohammad Odeh et al GCN 34543
Not found
 
 
, 34561
Not found
 
 
., H. Negoro (Nihon U). et al GCN 34544
Not found
 
 
., Brendan O'Connor et al GCN 34549
Not found
 
 
.,Dylan Dutton et al GCN 34556
Not found
 
 
., T. M. Parsotan et al GCN 34557
Not found
 
 
., U.Quadri et al GCN 34562
Not found
 
 
., Claudio Lopresti et al GCN 34566
Not found
 
 
., S. Leonini et al GCN 34573
Not found
 
 
) 
at following position

RA (J2000.0)   17:27:43.32
Dec (J2000.0) -16:12:19

with the following photometry:

    JD	           Mag	        Filter
2460181.317	13.69            V
2460181.32	13.74            V
2460181.323	13.66            V
2460181.326	13.59            V
2460181.329	13.63            V
2460181.332	13.55            V
2460181.335	13.54            V
2460181.338	13.62            V
2460181.341	13.55            V
	


JD	          Mag	       Filter
2460181.309	13.49            Rc
2460181.31	13.51            Rc
2460181.312	13.54            Rc
2460181.313	13.45            Rc
2460181.315	13.47            Rc
2460181.318	13.48            Rc
2460181.321	13.50            Rc
2460181.324	13.52            Rc
2460181.33	13.45            Rc
2460181.333	13.46            Rc
2460181.336	13.50            Rc
2460181.339	13.50            Rc
2460181.342	13.50            Rc



The magnitudes are calibrated with stars of the PanSTARRS catalog, espressed in AB system and are not corrected for the expected Galactic extinction.

The peculiar transient ( detected by other observatories ) is confirmed in our observations. Further observations are encouraged.