{
  "body": "V. Lipunov, V.Kornilov, E.Gorbovskoy, K.Zhirkov, N.Tyurina, P.Balanutsa, A.Kuznetsov, D. Vlasenko, \nG.Antipov, D.Zimnukhov, V.Senik, E.Minkina, A.Chasovnikov, V.Topolev, D.Kuvshinov,  D.Cheryasov, Ya.Kechin\n(Lomonosov Moscow State University, SAI, Physics Department),\n\nR. Podesta, C.Lopez, F. Podesta, C.Francile \n(Observatorio Astronomico Felix Aguilar OAFA),\n\nR. Rebolo, M. Serra \n(The Instituto de Astrofisica de Canarias),\n\nD. Buckley \n(South African Astronomical Observatory),\n\nO.A. Gres, N.M. Budnev\n(Irkutsk State University, API),\n\nL.Carrasco, J.R.Valdes, V.Chavushyan, V.M.Patino Alvarez, J.Martinez, A.R.Corella, L.H.Rodriguez \n(INAOE, Guillermo Haro Astrophysics Observatory),\n\nA. Tlatov, D. Dormidontov \n(Kislovodsk Solar Station of the Pulkovo Observatory),\n\nA. Gabovich, V.Yurkov \n(Blagoveschensk Educational State University)\n\n\nMASTER-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 S230531f errorbox  18909 sec after notice time and 19920 sec after trigger time at 2023-05-31 05:53:25 UT, with upper limit up to  17.4 mag. The observations began at zenith distance = 47 deg. The sun  altitude  is -69.7 deg. \n\nThe galactic latitude b = 21 deg., longitude l = 158 deg.\n\n\nReal time updated cover map and OT discovered available here: \nhttps://master.sai.msu.ru/site/master2/ligo_1.php?id=11920\n\nWe obtain a following upper limits.  \n\nTmid-T0  |      Date Time      |          Site       |             Coord (J2000)          |Filt.| Expt. | Limit| Comment\n_________|_____________________|_____________________|____________________________________|_____|_______|_______|________\n\n   20010 | 2023-05-31 05:53:25 |         MASTER-OAFA | (21h 47m 17.84s , -50d 05m 55.5s) |   C |   180 | 17.4 |        \nFilter C is a clear (unfiltred) band. \n\n\nThe observation and reduction will continue. \nThe message may be cited.\n\n",
  "circularId": 33902,
  "bibcode": "2023GCN.33902....1L",
  "subject": "LIGO/Virgo S230531f: Global MASTER-Net observations report",
  "createdOn": 1685514284021,
  "submitter": "Vladimir Lipunov at Moscow State U/Krylov Obs <lipunov@xray.sai.msu.ru>",
  "eventId": "LIGO/Virgo S230531f"
}