GCN Circular 25599

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.]