{
  "createdOn": 1745084639917,
  "circularId": 40179,
  "eventId": "GRB 250419A",
  "body": "\nV.Lipunov, A.Kuznetsov, G.Antipov, V.Topolev, K.Zhirkov, N.Tyurina, P.Balanutsa, A.Chasovnikov,\nYa.Kechin, V.Senik, K. Labzina, D.Vlasenko, E.Gorboskoy(Lomonosov MSU),\nO.Gress, N.Budnev (ISU),\nC.Francile,  F. Podesta, R.Podesta, E. Gonzalez (OAFA),\nA.Sosnovskij (Crao RAS),\nA. Tlatov, D. Dormidontov (Kislovodsk Solar Station of the Pulkovo Observatory),\nA. Gabovich, V.Yurkov (Blagoveschensk Educational StateUniversity),\nR.Rebolo (The Instituto de Astrofisica de Canarias),\nD.Buckley (SAAO),\nL.Carrasco, J.R.Valdes, V.Chavushyan, V.M.Patino Alvarez, J.Martinez,A.R.Corella, L.H.Rodriguez (INAOE, Guillermo Haro AstrophysicsObservatory)\n\nMASTER-OAFA robotic telescope  (Global MASTER-Net: http://observ.pereplet.ru,Lipunov et al., 2010, Advances in Astronomy, v. 2010, 30L)\nlocated in Argentina (OAFA observatory of San Juan National University)\nwas pointed to the SVOM Alert 250419.10 (trigger No 1745029772,13h 29m 32.88s , +07d 05m 09.6s, R=0.1525, Wang et al. GCN 40168, Ocelotl López et al. GCN40169, Xin etl al. GCN40170)\n3960 sec after trigger time at 2025-04-19 03:35:32 UT, with upper limit up to  19.9 mag.\nThe observations began at zenith distance = 39 deg. The sun  altitude  is -66.0 deg.\n\nThe galactic latitude b = 68 deg., longitude l = 330 deg.\n\nReal time updated cover map and OT discovered available here:\nhttps://master.sai.msu.ru/site/master2/observ.php?id=2847195\n\nWe obtained the following upper limits.\n\nTmid-T0  |      Date Time      |          Site       |             Coord (J2000)          |Filt.| Expt. | Limit| Comment\n    3991 | 2025-04-19 03:35:32 |         MASTER-OAFA | (13h 29m 02.64s , +07d 04m 50.6s) |   C |    60 | 19.7 |\n    5446 | 2025-04-19 03:59:47 |         MASTER-OAFA | (13h 28m 54.60s , +07d 03m 09.9s) |   C |    60 | 19.7 |\n    6895 | 2025-04-19 04:23:56 |         MASTER-OAFA | (13h 29m 35.13s , +07d 25m 23.4s) |   C |    60 | 19.6 |\n    6955 | 2025-04-19 04:23:56 |         MASTER-OAFA | (13h 29m 35.12s , +07d 25m 23.4s) |   C |   180 | 19.9 |  Coadd\n    8383 | 2025-04-19 04:48:45 |         MASTER-OAFA | (13h 29m 28.53s , +07d 25m 00.4s) |   C |    60 | 19.5 |\n    9666 | 2025-04-19 05:10:08 |         MASTER-OAFA | (13h 29m 34.89s , +07d 26m 24.5s) |   C |    60 | 19.4 |\n   10159 | 2025-04-19 05:18:20 |         MASTER-OAFA | (13h 29m 31.07s , +07d 26m 26.7s) |   C |    60 | 19.5 |\nFilter C is a clear (unfiltred) band.\n\nThere is MASTER OT J132937.28+070227.8 since 2025-04-19 03:35:32 with m_OT=18.0 (unfiltered, Lipunov et al. 2010, 2019, 2022, 2023) up to 2025-04-19 05:18:20UT\nat SVOM VT position (GCN 40170 Xin et al.)\n\nThe reduction will be continued",
  "submitter": "Vladimir Lipunov at Moscow State U/Krylov Obs <lipunov@xray.sai.msu.ru>",
  "subject": "GRB 250419A: MASTER optical afterglow observation",
  "bibcode": "2025GCN.40179....1L",
  "submittedHow": "email"
}