{
  "bibcode": "2021GCN.29887....1L",
  "body": "V. Lipunov, E. Gorbovskoy, V.Kornilov, N.Tyurina, P.Balanutsa, A.Kuznetsov, F.Balakin, \nV.Vladimirov, D. Vlasenko, I.Gorbunov, D.Zimnukhov, V.Senik, T.Pogrosheva,\nD.Kuvshinov,  D. Cheryasov\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, O.Ershova \n(Irkutsk State University, API),\n\nA. Tlatov, D. Dormidontov \n(Kislovodsk Solar Station of the Pulkovo Observatory),\n\nV. Yurkov, A. Gabovich, Yu. Sergienko \n(Blagoveschensk Educational State University)\n\n\n\n\nMASTER-Tavrida robotic telescope  (Global MASTER-Net: http://observ.pereplet.ru, Lipunov et al., 2010, Advances in Astronomy, vol. 2010, 30L)  located in Russia (Lomonosov MSU, SAI Crimea astronomical station) was pointed to the Swift GRB210422.74 (trigger No 1044678,01h 24m 33.36s , +42d 06m 36.0s, R=0.05) errorbox  39 sec after notice time and 23084 sec after trigger time at 2021-04-23 00:11:54 UT, with upper limit up to  16.3 mag. The observations began at zenith distance = 84 deg. The sun  altitude  is -24.0 deg. \n\nThe galactic latitude b = -20 deg., longitude l = 130 deg.\n\n\nReal time updated cover map and OT discovered available here: \nhttps://master.sai.msu.ru/site/master2/observ.php?id=1599524\n\nWe obtain a following upper limits.  \n\nTmid-T0  |          Site       |Filt.| Expt. | Limit| Comment\n_________|_____________________|_____|_______|______|________\n\n   23175 |      MASTER-Tavrida |   C |   180 | 16.2 |        \n   23374 |      MASTER-Tavrida |   C |   180 | 16.3 |        \nFilter C is a clear (unfiltred) band. \n\n\nThe observation and reduction will continue. \nThe message may be cited.",
  "circularId": 29887,
  "createdOn": 1619137341000,
  "email": "lipunov@xray.sai.msu.ru",
  "subject": "Swift GRB210422.74: Global MASTER-Net observations report",
  "submitter": "Vladimir Lipunov at Moscow State U/Krylov Obs  <lipunov@xray.sai.msu.ru>",
  "eventId": "GRB 210422.74"
}