{
  "subject": "GRB 180728A: MASTER early polarization and 19 days monitoring",
  "eventId": "GRB 180728A",
  "bibcode": "2018GCN.23143....1L",
  "createdOn": 1534451619000,
  "circularId": 23143,
  "submitter": "Vladimir Lipunov at Moscow State U/Krylov Obs  <lipunov@xray.sai.msu.ru>",
  "email": "lipunov@xray.sai.msu.ru",
  "body": "V. Lipunov, E. Gorbovskoy, N.Tiurina, D.Vlasenko, V.Kornilov, A.Kuznetsov,\nV.Chazov, I.  Gorbunov, D.Zimnukhov, D.Kuvshinov, \nP.Balanutsa,V.Vladimirov,\nLomonosov Moscow State University,SAI\n\nD. Buckley,\nSouth African Astronomical Observatory (SAAO)\n\nR. Rebolo, M. Serra, N. Lodieu, G. Israelian, L. Suarez-Andres\nThe Instituto de Astrofisica de Canarias (IAC)\n\nA. Tlatov, V.Senik, D. Dormidontov\nKislovodsk Solar Station of the Pulkovo Observatory\n\nR. Podesta, F. Podesta, C. Lopez, C.Francile\nObservatorio Astronomico Felix Aguilar (OAFA)\n\nH.Levato,\nInstituto de Ciencias Astronomicas, de la Tierra y del Espacio (ICATE)\n\nO. Gres, N.M.Budnev , Yu.Ishmuhametova\nIrkutsk State University (ISU)\n\nA. Gabovich, V. Yurkov, Yu. Sergienko\nBlagoveschensk Educational State University (BSPU)\n\nMASTER Global Robotic Net ( Lipunov et al., 2010, Advances in Astronomy, \nvol. 2010, 30L) inspected GRB 180728A\n(SwiftBAT GRB discovery : Starling et al. GCN 23046;\nMASTER optical counterpart discovery: Lipunov et al. GCN 23048;GCN23050;\nSwiftXRT: Perri et al. GCN 23049; Redshift, VLT: Rossi et al. GCN 23055;\nSN discovery,VLT: Izzo et al. GCN 23142).\nevery night since the discovery.\n\nThere are unfiltered limits at MASTER images and absolute magnitude of \nSN ( Izzo et al. GCN 23142) for\nOmega_Vac = 0.7 and H_0 = 70 km/s/Mpc and Galactic extinction 0.1 for our \nred ccd:\n\nDate_Time,UT            |   Exp,s | MASTER-Site |  m_lim| M\n\n2018-07-29 21:18:37.092 |    2340 | MASTER-SAAO |  21.8 | -16.3\n2018-07-30 21:07:24.839 |    1440 | MASTER-SAAO |  20.8 | -17.3\n2018-07-30 21:07:24.912 |    1440 | MASTER-SAAO |  21.4 | -16.7\n2018-08-01 19:11:32.906 |    1620 | MASTER-SAAO |  20.9 | -17.2\n2018-08-01 19:15:07.977 |    1620 | MASTER-SAAO |  20.9 | -17.2\n2018-08-02 17:03:40.025 |    3780 | MASTER-SAAO |  20.8 | -17.2\n2018-08-02 18:12:49.446 |    3960 | MASTER-SAAO |  20.9 | -17.2\n2018-08-03 17:53:21.097 |    4140 | MASTER-SAAO |  20.8 | -17.3\n2018-08-03 17:53:21.347 |    4140 | MASTER-SAAO |  21.1 | -17.0\n2018-08-03 23:21:10.842 |    3420 | MASTER-OAFA |  20.6 | -17.5\n2018-08-04 17:05:35.120 |    2700 | MASTER-SAAO |  20.9 | -17.2\n2018-08-04 17:12:46.879 |    2880 | MASTER-SAAO |  20.8 | -17.3\n2018-08-04 23:07:09.154 |     720 | MASTER-OAFA |  20.5 | -17.6\n2018-08-05 22:18:29.225 |    3240 | MASTER-SAAO |  20.8 | -17.3\n2018-08-05 22:22:04.704 |    3240 | MASTER-SAAO |  21.1 | -17.0\n2018-08-05 23:08:46.934 |    1260 | MASTER-OAFA |  21.5 | -16.5\n2018-08-06 18:46:19.565 |    3600 | MASTER-SAAO |  20.8 | -17.3\n2018-08-06 18:46:19.605 |    3600 | MASTER-SAAO |  20.8 | -17.3\n2018-08-07 00:26:41.653 |     900 | MASTER-OAFA |  20.4 | -17.7\n2018-08-07 03:30:36.096 |    2520 | MASTER-OAFA |  20.6 | -17.5\n2018-08-07 17:15:34.447 |    3780 | MASTER-SAAO |  20.9 | -17.2\n2018-08-07 18:23:07.857 |    3780 | MASTER-SAAO |  21.7 | -16.4\n2018-08-08 17:59:05.042 |    4140 | MASTER-SAAO |  20.8 | -17.3\n2018-08-08 18:02:42.597 |    4140 | MASTER-SAAO |  20.9 | -17.2\n2018-08-08 23:11:34.904 |    3240 | MASTER-OAFA |  21.9 | -16.2\n2018-08-09 18:55:17.807 |     540 | MASTER-SAAO |  20.8 | -17.2\n2018-08-09 18:58:54.517 |     540 | MASTER-SAAO |  20.8 | -17.2\n2018-08-09 23:04:26.723 |    3240 | MASTER-OAFA |  20.5 | -17.5\n2018-08-10 17:00:41.943 |    2520 | MASTER-SAAO |  20.9 | -17.1\n2018-08-11 00:08:05.570 |    4500 | MASTER-OAFA |  20.7 | -17.3\n2018-08-11 18:43:29.720 |    7020 | MASTER-SAAO |  20.9 | -17.1\n2018-08-11 23:12:32.140 |    3240 | MASTER-OAFA |  20.6 | -17.4\n2018-08-12 19:46:57.192 |    7560 | MASTER-SAAO |  22.1 | -15.9\n2018-08-12 19:46:57.246 |    7560 | MASTER-SAAO |  20.9 | -17.1\n2018-08-12 23:18:02.053 |    3240 | MASTER-OAFA |  19.8 | -18.2\n2018-08-13 07:43:55.504 |    3420 | MASTER-OAFA |  21.2 | -16.8\n\nWe have carried out preliminary photometry of MASTER early observations\n  (Lipunov et al. GCN 23048; GCN23050;) also we report about \nconsiderable polarization of optical radiation of gamma burst the first \nminute after its beginning.\n\nThis message can be cited."
}