TITLE: GCN CIRCULAR NUMBER: 25594 SUBJECT: LIGO/Virgo S190828j : No significant candidates in TAROT-GRANDMA observations DATE: 19/08/31 21:23:06 GMT FROM: Nelson Christensen at Obs.de la Cote dAzur,Nice S. Antier (APC), C. Lachaud (APC), N. Christensen (Artemis), B. Gendre (OzGrav-UWA), N. Ismayilov (SHAO), M. Boer (Artemis), L. Eymar (Artemis), A. Klotz (IRAP), K. Noysen (Artemis, IRAP), S. Basa (LAM), D. Corre (LAL), M. Coughlin (Caltech), D. Coward (OzGrav-UWA), J.G. Ducoin (LAL), P. Hello (LAL), N. Leroy (LAL), D. Turpin (NAOC), X. Wang (THU) report on behalf of the TAROT network and GRANDMA collaborations. We performed tiled observations of the LIGO/Virgo event S190828j with the TAROT-Chili (TCH), TAROT-Calern (TCA) and TAROT-Reunion (TRE) telescopes operating in the visible located respectively at La Silla ESO observatory (LaS/ESO), the Calern site at the Cote d'Azur Observatory and Les Makes astronomical observatory. The observation started for TCH on 08/28/19 07:05:39 UTC which corresponds approximately to 32 minutes after the GW trigger time. We performed the following tiled observations : +-------+------------+------------+---------+---------+---------+ | Tele | TStart | TEnd | RA | DEC | Proba | | scope | [UTC] | [UTC] | [deg] | [deg] | [%] | |-------+------------+------------+---------+---------+---------| | TCH | 2019-08-28 | 2019-08-30 | 312.95 | 12.768 | 0.1 | | | 07:05:39 | 03:48:14 | | | | | TCH | 2019-08-28 | 2019-08-30 | 309.933 | 9.05 | 0.1 | | | 07:34:47 | 03:55:02 | | | | | TCH | 2019-08-29 | 2019-08-30 | 314.525 | 27.707 | 0.1 | | | 00:24:53 | 01:31:01 | | | | | TCH | 2019-08-29 | 2019-08-30 | 319.388 | 21.777 | <0.1 | | | 03:00:41 | 06:37:09 | | | | | TCH | 2019-08-29 | 2019-08-30 | 314.558 | 13.161 | <0.1 | | | 03:07:29 | 06:43:58 | | | | | TCH | 2019-08-30 | 2019-08-30 | 213.626 | -61.777 | 0.2 | | | 03:34:54 | 03:41:24 | | | | |-------+------------+------------+---------+---------+---------| | TCA | 2019-08-28 | 2019-08-28 | 330.312 | 44.558 | 1.1 | | | 19:04:46 | 19:11:17 | | | | | TCA | 2019-08-28 | 2019-08-29 | 331.832 | 46.414 | 0.9 | | | 19:11:36 | 20:17:45 | | | | | TCA | 2019-08-28 | 2019-08-30 | 328.674 | 42.703 | 0.8 | | | 19:18:25 | 01:24:18 | | | | | TCA | 2019-08-28 | 2019-08-28 | 8.45 | 61.259 | 0.7 | | | 19:50:08 | 19:56:38 | | | | | TCA | 2019-08-28 | 2019-08-29 | 334.479 | 46.414 | 0.7 | | | 19:56:57 | 01:03:10 | | | | | TCA | 2019-08-28 | 2019-08-29 | 343.245 | 51.981 | 0.6 | | | 20:03:48 | 21:09:42 | | | | | TCA | 2019-08-28 | 2019-08-29 | 324.708 | 39.897 | 0.5 | | | 20:54:56 | 19:32:34 | | | | | TCA | 2019-08-28 | 2019-08-29 | 12.818 | 63.115 | 0.5 | | | 21:01:45 | 02:08:44 | | | | | TCA | 2019-08-28 | 2019-08-28 | 342.488 | 53.837 | 0.4 | | | 21:08:35 | 21:15:05 | | | | | TCA | 2019-08-28 | 2019-08-30 | 12.2 | 61.259 | 0.8 | | | 22:00:42 | 01:37:59 | | | | | TCA | 2019-08-28 | 2019-08-29 | 327.125 | 40.372 | 0.8 | | | 22:07:32 | 23:14:25 | | | | | TCA | 2019-08-28 | 2019-08-28 | 331.157 | 42.703 | 0.7 | | | 22:14:21 | 22:20:50 | | | | | TCA | 2019-08-28 | 2019-08-28 | 336.404 | 48.27 | 0.5 | | | 22:59:06 | 23:05:36 | | | | | TCA | 2019-08-28 | 2019-08-29 | 333.677 | 48.27 | 0.5 | | | 23:05:56 | 19:12:05 | | | | | TCA | 2019-08-28 | 2019-08-29 | 329.541 | 40.847 | 0.5 | | | 23:12:46 | 19:18:54 | | | | | TCA | 2019-08-28 | 2019-08-29 | 341.108 | 50.125 | 0.5 | | | 23:19:36 | 19:25:44 | | | | | TCA | 2019-08-29 | 2019-08-30 | 332.865 | 44.558 | 0.8 | | | 00:24:58 | 01:31:08 | | | | | TCA | 2019-08-29 | 2019-08-30 | 345.565 | 53.837 | 0.6 | | | 01:10:19 | 02:16:27 | | | | | TCA | 2019-08-29 | 2019-08-30 | 338.273 | 50.125 | 0.6 | | | 01:17:10 | 02:23:17 | | | | |-------+------------+------------+---------+---------+---------| | TRE | 2019-08-28 | 2019-08-28 | 324 | 36.818 | 3.6 | | | 21:35:08 | 21:41:42 | | | | | TRE | 2019-08-28 | 2019-08-28 | 317.922 | 28.636 | 2.7 | | | 21:48:24 | 21:54:58 | | | | | TRE | 2019-08-29 | 2019-08-29 | 312.857 | 16.364 | 1.3 | | | 15:43:28 | 15:49:56 | | | | | TRE | 2019-08-29 | 2019-08-29 | 309.767 | 12.273 | 0.6 | | | 16:15:23 | 16:21:51 | | | | | TRE | 2019-08-29 | 2019-08-29 | 321.081 | 32.727 | 3.3 | | | 20:11:45 | 20:18:19 | | | | | TRE | 2019-08-29 | 2019-08-29 | 315 | 24.545 | 1.8 | | | 20:24:55 | 20:31:29 | | | | | TRE | 2019-08-29 | 2019-08-29 | 325.946 | 32.727 | 0.7 | | | 20:56:14 | 21:02:42 | | | | +-------+------------+------------+---------+---------+---------+ TStart and TEnd refer respectively to the time of the first and last exposure for a given tile. Observations are not necessarily continuous in this interval. The Probability refers to the 2D spatial probability of the GW skymap enclosed in a given tile. Each tile is 1.9x1.9 degrees for TCA and TCH and 4.2x4.2 degrees for TRE. The coordinating observations cover about 26% of the cumulative probability of the bayestar skymap available on Aug 28, 2019 07:36:47 UTC. The typical limiting magnitude is 18.0 for a 60.0 s exposure for TCH and TCA and 17.0 for a 60.0 s exposure for TRE. The coverage map is available at: https://grandma-owncloud.lal.in2p3.fr/index.php/s/tG92ASJWw5C1tWV No significant transient candidates were found during our low latency analysis. GRANDMA (Global Rapid Advanced Network Devoted to the Multi-messenger Addicts) is a network of robotic telescopes connected all over the world with both photometry and spectrometry capabilities for Time-domain Astronomy (https://grandma.lal.in2p3.fr/). Details on the TAROT telescopes are available on the GRANDMA web pages or on http://tarot.obs-hp.fr/.