{
  "bibcode": "2021GCN.29751....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-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) was pointed to the Swift GRB210403.35 (trigger No 1040345,00h 11m 04.08s , -32d 59m 56.4s, R=0.05) errorbox  1478 sec after notice time and 1500 sec after trigger time at 2021-04-03 08:52:14 UT, with upper limit up to  18.8 mag. The observations began at zenith distance = 85 deg. The sun  altitude  is -25.4 deg. \n\nThe galactic latitude b = -80 deg., longitude l = 356 deg.\n\n\nReal time updated cover map and OT discovered available here: \nhttps://master.sai.msu.ru/site/master2/observ.php?id=1582518\n\nWe obtain a following upper limits.  \n\nTmid-T0  |          Site       |Filt.| Expt. | Limit| Comment\n_________|_____________________|_____|_______|______|________\n\n    1591 |         MASTER-OAFA |   C |   180 | 16.2 |        \n    2025 |         MASTER-OAFA |   C |   180 | 17.0 |        \n    2205 |         MASTER-OAFA |   C |   540 | 18.0 |  Coadd \n    3222 |         MASTER-OAFA |   C |   180 | 17.8 |        \n    3422 |         MASTER-OAFA |   C |   180 | 17.9 |        \n    3621 |         MASTER-OAFA |   C |   180 | 18.0 |        \n    3801 |         MASTER-OAFA |   C |   540 | 18.8 |  Coadd \n    3820 |         MASTER-OAFA |   C |   180 | 18.0 |        \n    4020 |         MASTER-OAFA |   C |   180 | 18.1 |        \n    4219 |         MASTER-OAFA |   C |   180 | 18.1 |        \n    4419 |         MASTER-OAFA |   C |   180 | 18.0 |        \nFilter C is a clear (unfiltred) band. \n\n\nThe observation and reduction will continue. \nThe message may be cited.",
  "circularId": 29751,
  "createdOn": 1617456029000,
  "email": "lipunov@xray.sai.msu.ru",
  "subject": "Swift GRB210403.35: Global MASTER-Net observations report",
  "submitter": "Vladimir Lipunov at Moscow State U/Krylov Obs  <lipunov@xray.sai.msu.ru>",
  "eventId": "GRB 210403.35"
}