{
  "bibcode": "2020GCN.26786....1W",
  "body": "J. Y. Wei (NAOC), S. Guillot (CNRS/IRAP), J. Wang (GXU), \nS. Basa (CNRS/LAM), X. H. Han (NAOC)\n\nreport on behalf of the SVOM Multi Messenger Astronomy and GWAC teams\n(http://www.svom.fr/en/svom-mma-and-gwac-team):\n\nWe observed 17 (~2550 square deg) sky regions to cover the skymap of the\nadvanced LIGO/Virgo trigger S200115j  (GCN # 26759), with SVOM/GWAC,\nat Xinglong Observatory. SVOM/GWAC is equipped with two sets of\nwide angle cameras:\n- FFOV cameras (FOV~900 square degrees/camera, aperture = 3.5 cm),\n- JFOV cameras (FOV~150 square degrees/camera, aperture = 18 cm).\n\nSVOM/GWAC currently comprises 4 FFOV cameras and 16 JFOV cameras,\nworking in the unfiltered band. The observations are operated in\ntime-series mode, taking one exposure every 25 seconds\n(20s exposure + 5s readout). The observed and processed regions enclosed\nan estimated 67.1% of the probability of the advanced LIGO/Virgo skymap.\nImages were taken between ~7 hours and ~18 hours after the GW trigger\ntime. The coordinates of the 17 sky regions observed and\ntheir observation times and covered probability are listed below:\n\nId Ra           Dec         start (UTC)       end (UTC)         Proba. Cam.\n1  05:50:26.3 51:50:22  2020-01-15 14:18:51 2020-01-15 14:46:00 0.003 JFOV\n2  07:26:21.8 64:13:01  2020-01-15 14:18:51 2020-01-15 14:46:00 0.004 JFOV\n3  09:44:22.8 68:18:18  2020-01-15 15:24:38 2020-01-15 15:53:38 0.010 JFOV\n4  16:31:30.7 -3:13:56  2020-01-15 22:03:45 2020-01-15 22:05:47 0.020 JFOV\n5  16:39:37.9 -14:35:58 2020-01-15 22:04:20 2020-01-15 22:14:51 0.040 JFOV\n6  03:19:17.3 13:34:55  2020-01-15 12:43:57 2020-01-15 13:12:07 0.116 JFOV\n7  03:19:57.0 01:29:44  2020-01-15 12:50:14 2020-01-15 13:12:07 0.058 JFOV\n8  02:29:35.0 01:23:54  2020-01-15 12:55:06 2020-01-15 13:12:07 0.251 JFOV\n9  02:42:06.7 -14:20:52 2020-01-15 12:53:27 2020-01-15 13:12:52 0.030 JFOV\n10 03:29:53.5 -2:41:46  2020-01-15 12:57:06 2020-01-15 13:12:52 0.001 JFOV\n11 04:20:51.2 47:50:40  2020-01-15 11:26:49 2020-01-15 11:56:36 0.071 JFOV\n12 04:10:55.1 36:07:24  2020-01-15 11:26:49 2020-01-15 11:56:38 0.043 JFOV\n13 02:59:22.0 35:09:36  2020-01-15 11:33:18 2020-01-15 14:15:11 0.005 JFOV\n14 04:06:04.5 47:32:04  2020-01-15 11:34:00 2020-01-15 14:15:11 0.070 JFOV\n15 04:00:51.0 35:21:07  2020-01-15 11:50:37 2020-01-15 14:15:11 0.050 JFOV\n16 05:51:31.2 64:35:19  2020-01-15 13:16:53 2020-01-15 13:44:55 0.033 JFOV\n17 05:32:23.9 52:57:41  2020-01-15 13:35:13 2020-01-15 13:44:55 0.018 JFOV\n\nThe sky coverage map is available at:\nhttp://cmm.svom.cn/gwpub/O3/S200115j/S200115j.png\n(user:svomo3 pwd:gwo3).\n\nWeather conditions were clear during the observations. The sky regions are\n> 80 degrees from the moon (~0.72 of lunar phase). An average 3-sigma\nlimiting magnitude of 16 mag in the R band was obtained in the single\nframes. No credible new source was detected by our online pipeline during\nfollow-up observations. A more detailed image analysis including\nco-addition is ongoing with our offline pipeline to search for transient\ncandidates.",
  "circularId": 26786,
  "createdOn": 1579183819000,
  "email": "hxh@nao.cas.cn",
  "subject": "LIGO/Virgo S200115j: no counterpart candidate in SVOM/GWAC observations",
  "submitter": "Xuhui Han at NAOC/SVOM  <hxh@nao.cas.cn>",
  "eventId": "LIGO/Virgo S200115j"
}