TITLE:   GCN CIRCULAR
NUMBER:  25338
SUBJECT: LIGO/Virgo S190814bv : No counterpart candidate in TAROT-GRANDMA observations
DATE:    19/08/15 13:27:35 GMT
FROM:    Nicolas Leroy at LAL  <leroy@lal.in2p3.fr>

A. Klotz (IRAP), V. Aivazyan (Iliauni), X. Zhang (THU),
R. Natsvlishvili (Iliauni), M. Boer (Artemis), N. Christensen
(Artemis), L. Eymar (Artemis), K. Noysena (Artemis, IRAP), S. Antier
(APC), S. Basa (LAM), D. Corre (LAL), D. Coward (OzGrav-UWA),
J.G. Ducoin (LAL), B. Gendre (OzGrav-UWA), P. Hello (LAL),
C. Lachaud (APC), N. Leroy (LAL), D. Turpin (NAOC)

Report on behalf of the TAROT network and GRANDMA collaborations.

We performed tiled observations of LIGO/Virgo S190814bv event with the
  TAROT-Calern (TCA) telescope operating in the visible located at
Calern site at the Cote d'Azur observatory.
The observation started on 08/15/19 00:09:41 UTC which corresponds
approximately to 180 minutes after the GW trigger time.

We performed the following tiled observations :

+------------+------------+---------+---------+---------+

| TStart     | TEnd       | RA      | DEC     |   Proba |

| [UTC]      | [UTC]      | [deg]   | [deg]   |     [%] |

|------------+------------+---------+---------+---------|

| 2019-08-15 | 2019-08-15 | 14.078  | -23.196 |     5   |

| 00:09:41   | 02:24:40   |         |         |         |

| 2019-08-15 | 2019-08-15 | 9.945   | -21.34  |     1.3 |

| 00:29:08   | 01:05:38   |         |         |         |

| 2019-08-15 | 2019-08-15 | 10.056  | -23.196 |     3.5 |

| 00:49:07   | 02:29:14   |         |         |         |

| 2019-08-15 | 2019-08-15 | 12.067  | -23.196 |    16   |

| 02:11:19   | 02:17:49   |         |         |         |

| 2019-08-15 | 2019-08-15 | 11.934  | -21.34  |     1.7 |

| 02:31:49   | 02:38:20   |         |         |         |

+------------+------------+---------+---------+---------+


TStart and TEnd refers 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. These observations cover about 27% of the cumulative
probability of the bayestar skymap with HLV.
The typical limiting magnitude is 18.0 for a 60.0 s exposure.

The coverage map is available at:
https://grandma-owncloud.lal.in2p3.fr/index.php/s/7Y1Zos9G2n0rrrs

No serious 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 TCA telescope  are available on the GRANDMA web pages
or on  http://tarot.obs-hp.fr/.

This circular is citable.