TITLE: GCN CIRCULAR NUMBER: 25599 SUBJECT: LIGO/Virgo S190814bv : No significant candidates in TAROT-GRANDMA observations DATE: 19/09/01 21:07:56 GMT FROM: Nelson Christensen at Obs.de la Cote dAzur,Nice D. Corre (LAL), M. Blazek (HETH/IAA-CSIC), A. Klotz (IRAP), N. Christensen (Artemis), M. Boer (Artemis), L. Eymar (Artemis), K. Noysena (Artemis, IRAP), S. Antier (APC), S. Basa (LAM), D. Coward (OzGrav-UWA), J.G. Ducoin (LAL), B. Gendre (OzGrav-UWA), P. Hello (LAL), D. A. Kann (HETH/IAA-CSIC), C. Lachaud (APC), N. Leroy (LAL), D. Turpin (NAOC), X. Wang (THU) report on behalf of the TAROT network and GRANDMA collaborations: We performed tiled observations of LIGO/Virgo event S190814bv (GCN #25324) with the TAROT-Reunion (Les Makes Observatory, La Reunion Island, France) telescope operating in clear filter. The observations started on 08/14/19 21:41:19 UTC which corresponds approximately to 31 minutes after the GW trigger time. We performed the following tiled observations : +------------+------------+---------+---------+---------+ | TStart | TEnd | RA | DEC | Proba | | [UTC] | [UTC] | [deg] | [deg] | [%] | |------------+------------+---------+---------+---------| | 2019-08-14 | 2019-08-14 | 9.3506 |-28.6364 | 0.4 | | 21:41:19 | 23:12:44 | | | | | 2019-08-14 | 2019-08-14 | 0.0000 |-32.7273 | < 0.1 | | 22:02:49 | 23:25:55 | | | | | 2019-08-14 | 2019-08-16 | 13.500 |-24.5454 | 76.0 | | 22:14:55 | 00:48:18 | | | | | 2019-08-14 | 2019-08-14 | 20.6897 | -8.1818 | < 0.1 | | 22:28:09 | 23:51:15 | | | | | 2019-08-14 | 2019-08-15 |354.8571 |-36.8182 | < 0.1 | | 22:47:06 | 00:09:59 | | | | | 2019-08-14 | 2019-08-14 | 4.6753 |-28.6364 | < 0.1 | | 23:00:04 | 23:04:30 | | | | | 2019-08-15 | 2019-08-15 | 9.0000 |-24.5454 | 6.3 | | 00:15:59 | 00:46:01 | | | | | 2019-08-15 | 2019-08-21 | 24.324 |-32.727 | 7.4 | | 19:54:58 | 01:01:29 | | | | +------------+------------+---------+---------+---------+ 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 4.2x4.2 degrees. These observations cover about 89% of the cumulative probability of the LALInference skymap with HLV (posted at Aug 15, 2019 09:07:19 UTC) The typical limiting magnitude is 16.0 for a 60.0 s exposure due to bad conditions of observations. No serious transient candidates were found during our low latency analysis. The coverage map is available at: https://grandma-owncloud.lal.in2p3.fr/index.php/s/0aSCYiO1XqzHJkx Further analysis of the field (ra:13.500,dec:-24.5454) observed 64 min after the GW trigger time covering 76% of the LALInference skymap has been performed. No sources were found giving an upper limit at 16 mag for a possible optical counterpart. We have also found no source (3 sigma) at locations of desgw-190814j, desgw-190814m, desgw-190814o (GCN #25425), DG19hqpgc, DG19tzyhc, DG19wgmjc, DG19sevhc (GCN #25362), DG19vodmc, DG19gcwjc, DG19rzhoc, DG19tvtnc, DG19sbzkc, DG19hqhjc (GCN #25393), PS19epf, PS19eph (GCN #25356), desgw-190814a (GCN #25336), desgw-190814q (GN #25438). 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 TRE telescope are available on the GRANDMA web pages or on http://tarot.obs-hp.fr/. [GCN OPS NOTE(02sep19): Per author's request, MB's affiliation was corrected, and DAK was added to the author list.]