TITLE:   GCN CIRCULAR
NUMBER:  33975
SUBJECT: LIGO/Virgo S230616j: Global MASTER-Net observations report
DATE:    23/06/16 06:53:34 GMT
FROM:    Vladimir Lipunov at Moscow State U/Krylov Obs <lipunov@xray.sai.msu.ru>

V. Lipunov, V.Kornilov, E.Gorbovskoy, K.Zhirkov, N.Tyurina, P.Balanutsa, A.Kuznetsov, D. Vlasenko, 
G.Antipov, D.Zimnukhov, V.Senik, E.Minkina, A.Chasovnikov, V.Topolev, D.Kuvshinov,  D.Cheryasov, Ya.Kechin
(Lomonosov Moscow State University, SAI, Physics Department),

R. Podesta, C.Lopez, F. Podesta, C.Francile 
(Observatorio Astronomico Felix Aguilar OAFA),

R. Rebolo, M. Serra 
(The Instituto de Astrofisica de Canarias),

D. Buckley 
(South African Astronomical Observatory),

O.A. Gres, N.M. Budnev
(Irkutsk State University, API),

L.Carrasco, J.R.Valdes, V.Chavushyan, V.M.Patino Alvarez, J.Martinez, A.R.Corella, L.H.Rodriguez 
(INAOE, Guillermo Haro Astrophysics Observatory),

A. Tlatov, D. Dormidontov 
(Kislovodsk Solar Station of the Pulkovo Observatory),

A. Gabovich, V.Yurkov 
(Blagoveschensk Educational State University)


MASTER-OAFA robotic telescope  (Global MASTER-Net: http://observ.pereplet.ru, Lipunov et al., 2010, Advances in Astronomy, vol. 2010, 30L)  located in Argentina (OAFA observatory of San Juan National University) started inspect of the LIGO/Virgo S230616j errorbox  10 sec after notice time and 139 sec after trigger time at 2023-06-16 04:26:33 UT, with upper limit up to  19.2 mag. The observations began at zenith distance = 71 deg. The sun  altitude  is -82.1 deg. 

The galactic latitude b = -56 deg., longitude l = 240 deg.


Real time updated cover map and OT discovered available here: 
https://master.sai.msu.ru/site/master2/ligo_1.php?id=12062

We obtain a following upper limits.  

Tmid-T0  |      Date Time      |          Site       |             Coord (J2000)          |Filt.| Expt. | Limit| Comment
_________|_____________________|_____________________|____________________________________|_____|_______|_______|________

     229 | 2023-06-16 04:26:33 |         MASTER-OAFA | (13h 22m 12.19s , +09d 26m 42.0s) |   C |   180 | 19.1 |        
     647 | 2023-06-16 04:33:31 |         MASTER-OAFA | (13h 01m 51.41s , -09d 34m 12.2s) |   C |   180 | 19.2 |        
    1052 | 2023-06-16 04:40:16 |         MASTER-OAFA | (13h 10m 01.51s , -09d 32m 40.2s) |   C |   180 | 19.3 |        
Filter C is a clear (unfiltred) band. 


The observation and reduction will continue. 
The message may be cited.