{
  "bibcode": "2019GCN.24136....1H",
  "body": "X.H. Han (NAOC), J.Y. Wei (NAOC), C. Wu (NAOC), L.P. Xin (NAOC),\nD. Turpin (NAOC), N. LEROY (CNRS/LAL), S. ANTIER (CNRS/APC/CNES),\nL. Huang (NAOC), Y. Xu (NAOC), H.B. Cai (NAOC), J. Wang (NAOC),\nX.M. Lu (NAOC), Y.L. Qiu (NAOC), J.S. Deng (NAOC), L. Jia (NAOC),\nS.C. Zou (NAOC), S.F. Liu (NAOC), Q.C. Feng (NAOC), H.L. Li (NAOC),\nD.W. Xu (NAOC), Y.J. Xiao (NAOC), W.L. Dong (NAOC), Y.T. Zheng (NAOC),\nP. P. Zhang (NAOC), R.S. Zhang (NAOC), E.W. Liang (GXU), X.G. Wang (GXU),\nZ.G. Dai (NJU), X.Y. Wang (NJU), Y.G. Yang (HBNU), J.R. Mao (YNAO),\nB. Cordier (CEA/AIM), S. Basa (CNRS/LAM), J.L. Atteia (UPS/IRAP),\nD. Gotz (CEA/AIM), A. Claret (CEA/AIM), C. Lachaud (CNRS/APC),\nR. Duque (CNRS/IAP), N. Dagoneau (CEA/AIM) S.N. Zhang (IHEP),\nB.B. Wu (IHEP),\nreport on behalf of the SVOM Ground Follow-up Group:\n\n\nWe observed 7 sky regions (total: 1100 square degrees) to cover the\nskymap of the advanced LIGO/Virgo trigger S190412M, with SVOM/GWAC,\nat Xinglong Observatory equipped with a set of two types of wide angle\ncameras: FFOV cameras (FOV~900 square degrees/camera, aperture = 3.5\ncm) and JFOV cameras (FOV~150 square degrees/camera, aperture = 18\ncm). SVOM/GWAC currently comprises 4 FFOV cameras and 16 JFOV cameras,\nworking with unfiltered band. The observations are operated in time-series\nmode, taking one exposure every 15 seconds (10s exposure + 5s readout).\nWe estimate a 95% prior probability that these 7 regions contain the\ntrue location of the source.\nThe coordinates of the 7 regions and observation time are list following:\n\nNo. Ra Dec start-obs(UTC) end-obs(UTC) Telescope_ID\n1 12:16:08.501 +13:42:34.43 2019-04-12 14:21:03 2019-04-12 14:53:31 2\n2 13:04:12.375 +13:07:23.42 2019-04-12 14:21:03 2019-04-12 14:53:31 2\n3 13:01:14.699 +01:23:57.03 2019-04-12 14:21:03 2019-04-12 14:53:31 2\n4 14:15:50.897 +35:59:33.54 2019-04-12 14:05:51 2019-04-12 14:20:11 2\n5 15:42:30.509 +35:59:41.27 2019-04-12 14:05:51 2019-04-12 14:20:11 2\n6 12:16:49.785 +01:39:44.92 2019-04-12 14:21:03 2019-04-12 14:53:31 2\n7 14:47:20.959 +36:20:07.37 2019-04-12 14:05:51 2019-04-12 14:20:11 2\n\nThe covering map is available at:\nhttp://cmm.svom.cn/gwpub/O3/S190412m/S190412m_GWAC.png\n(user:svomo3 pwd:gwo3)\n\nThe first image was taken ~8 hours after the event trigger time. The\nweather conditions were bad (cloudy) during the observations. A 3\nsigma limiting magnitude of about 14 mag in R band is obtained in\nour single frames. No credible new source is detected by our online\npipeline.\nA more detailed image analysis including co-addition is ongoing with\nour offline pipeline to search for transient candidates.\n\nThis circular is citable.",
  "circularId": 24136,
  "createdOn": 1555721163000,
  "email": "wuchao.lamost@gmail.com",
  "subject": "LIGO/Virgo S190412m: SVOM/GWAC observations of the initial skymap",
  "submitter": "Chao Wu at NAOC  <wuchao.lamost@gmail.com>",
  "eventId": "LIGO/Virgo S190412m"
}