{
  "bibcode": "2019GCN.26571....1W",
  "body": "C. Wu (NAOC), M. Dennefeld (IAP/CNRS/SU) , X. Wang (GXU), \nR. Duque (CNRS/IAP), S.S. Sun (GXU)\n\nreport on behalf of the SVOM Multi Messenger Astronomy and GWAC teams\n(http://www.svom.fr/en/svom-mma-and-gwac-team <http://www.svom.fr/en/svom-mma-and-gwac-team>):\n\nWe observed  37 150-sq. deg sky regions to cover the skymap of the\nadvanced LIGO/Virgo trigger S191222n  (GCN # 26543), 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 36.9% of the probability of the advanced LIGO/Virgo skymap.\nImages were taken between ~8.8 minutes and ~16.63 hours after the GW trigger\ntime. The coordinates of the 37 sky regions observed after the trigger and\ntheir observation times and covered probability are listed below:\n\nId Ra           Dec         start (UTC)       end (UTC)         Cov. Cam.\n1   07:24:00.24 53:02:52.80    2019-12-22 12:32:11 2019-12-22 12:59:41    0.021   JFOV\n2   05:50:52.75 52:05:58.20    2019-12-22 12:17:05 2019-12-22 12:23:10    0.029   JFOV\n3   07:30:30.00 48:26:49.56    2019-12-22 13:37:33 2019-12-22 14:39:54    0.017   JFOV\n4   08:31:26.64 36:09:36.36    2019-12-22 13:41:12 2019-12-22 14:39:54    0.001   JFOV\n5   08:26:42.72 47:40:49.80    2019-12-22 13:28:55 2019-12-22 13:49:59    0.017   JFOV\n6   08:57:33.12 48:28:44.40    2019-12-22 14:40:49 2019-12-22 15:08:43    0.014   JFOV\n7   09:58:28.80 36:10:45.48    2019-12-22 14:40:49 2019-12-22 15:08:44    0.010   JFOV\n8   09:03:17.76 36:28:34.68    2019-12-22 14:40:49 2019-12-22 15:08:44    0.005   JFOV\n9   09:53:40.32 47:42:14.40    2019-12-22 14:56:46 2019-12-22 15:41:54    0.004   JFOV\n10  08:46:46.08 35:05:22.92    2019-12-22 14:41:22 2019-12-22 15:41:54    0.001   JFOV\n11  11:07:09.36 14:33:39.96    2019-12-22 17:28:48 2019-12-22 17:56:42    0.008   JFOV\n12  11:52:22.32 02:14:49.49    2019-12-22 17:28:48 2019-12-22 17:56:43    0.024   JFOV\n13  11:43:29.28 13:47:45.24    2019-12-22 17:28:23 2019-12-22 17:56:20    0.011   JFOV\n14  11:43:07.44 01:33:46.40    2019-12-22 17:28:23 2019-12-22 17:55:56    0.017   JFOV\n15  13:05:04.80 -14:43:42.60   2019-12-22 19:55:37 2019-12-22 20:13:24    0.059   JFOV\n16  12:19:09.84 -14:28:44.04   2019-12-22 19:45:30 2019-12-22 20:13:24    0.029   JFOV\n17  12:54:54.96 -3:11:46.03    2019-12-22 19:45:37 2019-12-22 20:13:35    0.015   JFOV\n18  01:16:50.26 13:21:14.40    2019-12-22 10:55:10 2019-12-22 10:56:23    0.002   JFOV\n19  01:31:43.61 -2:38:38.15    2019-12-22 12:00:30 2019-12-22 12:28:24    0.011   JFOV\n20  01:31:11.11 -14:41:56.76   2019-12-22 12:00:30 2019-12-22 12:28:25    0.003   JFOV\n21  01:15:33.36 -15:41:16.80   2019-12-22 12:32:50 2019-12-22 13:00:47    0.002   JFOV\n22  02:22:18.02 19:03:32.04    2019-12-22 11:36:09 2019-12-22 11:56:47    0.039   JFOV\n23  01:35:19.34 19:18:38.16    2019-12-22 11:51:07 2019-12-22 11:56:47    0.004   JFOV\n24  01:20:10.46 18:12:47.16    2019-12-22 11:34:30 2019-12-22 11:57:11    0.001   JFOV\n25  02:48:12.86 31:22:33.96    2019-12-22 10:12:47 2019-12-22 10:39:04    0.047   JFOV\n26  03:43:25.08 30:52:54.84    2019-12-22 10:26:10 2019-12-22 10:28:04    0.012   JFOV\n27  02:50:44.57 19:20:33.36    2019-12-22 10:19:15 2019-12-22 10:39:04    0.021   JFOV\n28  02:33:21.58 30:19:24.96    2019-12-22 10:10:30 2019-12-22 10:38:27    0.037   JFOV\n29  03:28:18.70 18:23:05.64    2019-12-22 10:16:10 2019-12-22 10:38:27    0.022   JFOV\n30  02:35:25.70 18:14:51.72    2019-12-22 10:11:43 2019-12-22 10:38:27    0.032   JFOV\n31  05:29:11.35 53:00:20.88    2019-12-22 13:03:21 2019-12-22 13:31:15    0.032   JFOV\n32  04:15:03.79 53:17:51.36    2019-12-22 13:03:45 2019-12-22 13:23:58    0.019   JFOV\n33  04:36:43.78 48:22:15.60    2019-12-22 11:11:19 2019-12-22 11:25:29    0.039   JFOV\n34  04:42:32.40 36:22:20.28    2019-12-22 11:14:09 2019-12-22 11:20:13    0.002   JFOV\n35  04:20:09.24 47:15:37.80    2019-12-22 11:16:02 2019-12-22 11:27:22    0.042   JFOV\n36  05:32:53.42 47:36:12.96    2019-12-22 11:10:51 2019-12-22 11:25:51    0.024   JFOV\n37  04:26:06.91 35:13:31.80    2019-12-22 10:57:54 2019-12-22 11:24:14    0.003   JFOV\n\n\nThe sky coverage map is available at:\nhttp://cmm.svom.cn/gwpub/O3/S191222n/S191222n.png <http://cmm.svom.cn/gwpub/O3/S191222n/S191222n.png>\n(user:svomo3 pwd:gwo3).\n\nWeather conditions were clear during the observations. 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": 26571,
  "createdOn": 1577155216000,
  "email": "hxh@nao.cas.cn",
  "subject": "LIGO/Virgo S191222n: no counterpart candidate in SVOM/GWAC observations",
  "submitter": "Xuhui Han at NAOC/SVOM  <hxh@nao.cas.cn>",
  "eventId": "LIGO/Virgo S191222n"
}