TITLE:   GCN CIRCULAR
NUMBER:  33965
SUBJECT: LIGO/Virgo S230615i: Global MASTER-Net observations report
DATE:    23/06/15 07:44:53 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 S230615i errorbox  204 sec after notice time and 260 sec after trigger time at 2023-06-15 07:31:12 UT, with upper limit up to  16.3 mag. The observations began at zenith distance = 78 deg. The sun  altitude  is -50.3 deg. 

The galactic latitude b = 24 deg., longitude l = 67 deg.


Real time updated cover map and OT discovered available here: 
https://master.sai.msu.ru/site/master2/ligo_1.php?id=12020

We obtain a following upper limits.  

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

     285 | 2023-06-15 07:31:12 |         MASTER-OAFA | (18h 11m 09.70s , +40d 46m 37.6s) |   C |    50 | 15.6 |        
     377 | 2023-06-15 07:32:33 |         MASTER-OAFA | (18h 11m 09.55s , +40d 44m 43.5s) |   C |    70 | 16.0 |        
     485 | 2023-06-15 07:34:16 |         MASTER-OAFA | (18h 11m 11.92s , +40d 46m 20.9s) |   C |    80 | 16.3 |        
     611 | 2023-06-15 07:36:08 |         MASTER-OAFA | (18h 11m 05.25s , +40d 45m 43.9s) |   C |   110 | 16.2 |        
Filter C is a clear (unfiltred) band. 


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