{
  "bibcode": "2018GCN.23023....1L",
  "body": "V. Lipunov, E. Gorbovskoy, N.Tiurina, D.Vlasenko, V.Kornilov, A.Kuznetsov, \nV.Chazov, I.  Gorbunov, D.Zimnukhov, D.Kuvshinov, P.Balanutsa,\nV.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-Amur robotic telescope (MASTER-Net: http://observ.pereplet.ru, \nLipunov et al., 2010, Advances in Astronomy, vol. 2010, 30L) located in \nRussia (Blagoveschensk State Pedagogical University) was pointed to the \nSwift GRB180720B (Siegel et al., GCN Circ #22973) 113 sec after trigger \ntime at 2018-07-20 14:23:37 UT.\nSo as the GRB was 4.6 degrees above the horizont, the good observations \nstarted on 2018-07-20 15:21:50UT.\n\nGalaxy latitude b = -63.07 degree.\nThe moon (58 % bright part) is 9 degrees above the horizon. The distance \nbetween  moon and  object was 143.\nThe sun  altitude  was -17.19 degree.\nThe object observed till 2018-07-20 15:47:58\n\nMASTER-SAAO robotic telescope (MASTER-Net: http://observ.pereplet.ru, \nLipunov et al., 2010, Advances in Astronomy, vol. 2010, 30L) located in \nSouth Africa (South African Astronomical observatory) was pointed to \nGRB180720B 27260 sec after trigger time at 2018-07-19 20:56:09 UT as \nMASTER's LAT (Bissaldi et al GCN22980)alert inspection with polarization \nfilters.\n\nMASTER-SAAO auto-detection system ( Lipunov et al., \"MASTER Global Robotic \nNet\", Advances in Astronomy, 2010, 30L )\n  discovered bright OT source at (RA, Dec) = 00h 02m 06.92s -02d 55m 05.6s \non  2018-07-19 20:56:09  UT.\n\nThe OT  magnitude is ~16.8m .\n\nThere is no minor planet at this place.\nWe have reference image on 2016-05-04.12293 UT with  unfiltered mlim =  18.1m.\n\n\nThe observations made on zenit distance = 16.7 degrees, galaxy latitude b \n= -74.37 degree. The moon (61 % bright part) was 24 degrees above the \nhorizon.The sun  altitude  was -63.7 degree.\n\nMASTER-SAAO reobserved this area on 2018-07-21 22:28:10-22:54:51UT as \nMASTER's MAXI (Negoro et al GCN 22993)  alert inspection  with mlim=20.2 \nand unfiltered m_OT~19.1\n\nThe discovery and reference images are \nhttp://master.sai.msu.ru/static/OT/MASTERGRB180720B.jpg\n\n\nMASTER-Kislovodsk robotic telescope (MASTER-Net: \nhttp://observ.pereplet.ru, Lipunov et al., 2010, Advances in Astronomy, \nvol. 2010, 30L) located in Russia (Pulkovo Solar Station) was pointed to \nthe GRB180720B (Siegel et al., GCN Circ #22973) 27457 sec after trigger \ntime at 2018-07-20 21:59:21 UT .\nOn our first (180s exposure)  set MASTER-Kislovodsk auto-detection system \ndiscovered OT with m_OT~17.0,  automatical  mlim~17.6.\n\nThe observations made on zenit distance = 25.66 degrees, galaxy latitude b \n= -63.07 degree.\nThe moon (61 % bright part) is below the horizon(The altitude of Moon is \n-8). The distance between  moon and  object is 138\nThe sun  altitude  is -24.87 degree.\nThe object observed till 2018-07-20 22:19:52\n\nMASTER-IAC robotic telescope (MASTER-Net: http://observ.pereplet.ru, \nLipunov et al., 2010, Advances in Astronomy, vol. 2010, 30L) located in \nSpain (IAC Teide Observatory) was pointed to the GRB180720B (Siegel et \nal., GCN Circ #22973) 44691 sec after trigger time at 2018-07-21 02:46:35 \nUT . On our first (60s exposure)  MASTER-IAC auto-detection system \ndiscovered  optical transient within Swift error-box  with automatical \nmagnitude ~18.0.\n\nThe observations made on zenit distance = 43.01 degrees, galaxy latitude b \n= -63.07 degree.\nThe moon (63 % bright part) is below the horizon(The altitude of Moon is \n-15). The distance between  moon and  object is 136\nThe sun  altitude  is -36.01 degree.\nThe object observed till 2018-07-21 03:03:36\n\nThe visibility GRB error box (coord:0.5279, -2.9170 error_box: 0.05)\nat trigger time at different MASTER sites:\n\nobj: -47.70 sun:  29.73 - Tavrida (Crimea, Russia)\nobj: -41.62 sun:  72.28 - IAC, Teide, (Tenerife, Spain)\nobj: -54.25 sun:  15.39 - SAAO (Sutherland, SA)\nobj: -46.85 sun:  23.59 - Kislovodsk (Russia)\nobj: -29.98 sun:  15.28 - Ural(Kourovka, Russia)\nobj: -10.74 sun: -8.46  - Tunka (near Baykal Lake, Russia)\nobj:  4.55  sun: -17.19 - Amur(Blagoveschensk)\nobj:  6.72  sun:  27.64 - OAFA (Argentina)\n\n\nThe message may be cited.",
  "circularId": 23023,
  "createdOn": 1532347040000,
  "email": "lipunov@xray.sai.msu.ru",
  "subject": "GRB 180720B: MASTER Global Net OT observations",
  "submitter": "Vladimir Lipunov at Moscow State U/Krylov Obs  <lipunov@xray.sai.msu.ru>",
  "eventId": "GRB 180720B"
}