GCN Circular 24126

M. Boer, N. Christensen, L. Eymar (CNRS-UCA-OCA ARTEMIS), A. Klotz,
K. Noysena (CNRS-UPS IRAP), S. Antier (CNRS-CEA-UP7 APC), S. Basa
(CNRS-LAM), D. Corre (CNRS-UPSud LAL), M. Coughlin (Caltech),
D. Coward (OzGrav-UWA),�� J.-G. Ducoin (CNRS-UPSud LAL),
B. Gendre (OzGrav-UWA), P. Hello (CNRS-UPSud LAL),
C. Lachaud (CNRS-CEA-UP7 APC), N. Leroy (CNRS-UPSud LAL), D. Turpin (NAOC)
report on behalf of the TAROT and GRANDMA collaborations.

We performed tiled observations of LIGO-Virgo S190412m (GCNC #24098) event
with the TCA (Calern Observatory, OCA, France) and TRE (Les Makes
Observatory, La R��union Island, France) telescopes in Clear filter.
The observations started at 2019-04-12 15:39:00 UTC, about 10h after the GW
trigger time.

We performed the following tiled observations :

For TRE
+-------------------+---------------------+--------+-------+-------+
Tstart�������������������������� | Tend������������������������������ | RA�������� | DEC���� | Proba |
[UTC time]������������������ | [UTC time]������������������ | [deg]�� | [deg] | [%] |
+-------------------+---------------------+--------+-------+-------|
2019-04-12 18:39:12 | 2019-04-12 22:48:35 | 216.00 | 34.29 | 20.97 |
2019-04-12 18:48:00 | 2019-04-12 22:57:29 | 221.14 | 34.29 | 14.50 |
2019-04-12 19:51:03 | 2019-04-12 23:06:35 | 226.29 | 34.29 | 9.70 |
2019-04-12 18:03:00 | 2019-04-12 23:15:35 | 214.05 | 30.00 | 9.50 |
2019-04-12 16:44:21 | 2019-04-12 21:18:29 | 195.56 | 17.14 | 7.22 |
2019-04-12 15:39:01 | 2019-04-12 22:30:40 | 190.84 | 12.86 | 6.65 |
2019-04-12 15:52:37 | 2019-04-12 22:39:34 | 191.11 | 17.14 | 4.89 |
+-------------------+---------------------+--------+-------+-------+

For TCA
+-------------------+---------------------+--------+-------+-------+
Tstart�������������������������� | Tend������������������������������ | RA�������� | DEC���� | Proba |
[UTC time]������������������ | [UTC time]������������������ | [deg]�� | [deg] | [%] |
+-------------------+---------------------+--------+-------+-------|
2019-04-12 21:36:03 | 2019-04-13 02:57:34 | 214.70 | 33.64 | 7.23 |
2019-04-12 19:39:05 | 2019-04-13 03:06:35 | 213.02 | 31.82 | 6.49 |
2019-04-12 19:48:05 | 2019-04-13 02:12:36 | 215.48 | 31.82 | 6.24 |
2019-04-12 21:00:04 | 2019-04-13 03:24:35 | 216.87 | 33.64 | 4.96 |
2019-04-12 20:06:03 | 2019-04-13 03:33:35 | 223.34 | 33.64 | 4.83 |
2019-04-12 21:18:05 | 2019-04-12 03:42:35 | 219.04 | 33.64 | 4.43 |
2019-04-12 21:27:04 | 2019-04-12 03:51:35 | 217.78 | 33.46 | 3.74 |
+-------------------+---------------------+--------+-------+-------+

The Probability refers to the 2D spatial probability of the
GW skymap enclosed in a given tile. The size of the tiles are 4.2x4.2 deg2
for TRE and 1.8 x 1.8 deg2 for TCA.
These observations cover 73% and 38% of the 90% GW probability skymap for
TRE and TCA respectively. The typical 3 sigma limiting magnitude for a
2 minute exposure is 17 for TRE and 18 for TCA. Results of the on-going
analysis�� will be reported in a later GCNC.


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/

This circular is citable.