[vsnet-grb-info 22228] LIGO/Virgo S190426c: OAJ-GRANDMA observation report

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  24327
SUBJECT: LIGO/Virgo S190426c: OAJ-GRANDMA observation report
DATE:    19/04/28 11:20:48 GMT
FROM:    Martin Blazek at HETH/IAA-CSIC  <alf at iaa.es>

M. Blazek (HETH/IAA-CSIC), D. Corre (LAL), E. Howell (OzGrav-UWA),
N. Christensen (Artemis), M. Vardosanidze (Iliauni), D. A. Kann
(HETH/IAA-CSIC), K. Bensch (HETH/IAA-CSIC), L. Izzo (HETH/IAA-CSIC),
C. Thoene (HETH/IAA-CSIC), A. de Ugarte Postigo (HETH/IAA-CSIC,
DARK/NBI), S. Antier (APC), S. Basa (LAM), M. Boer (Artemis),
M. Coughlin (Caltech), D. Coward (OzGrav-UWA), J.G. Ducoin (LAL),
B. Gendre (OzGrav-UWA), P. Hello (LAL), A. Klotz (IRAP),
C. Lachaud (APC), N. Leroy (LAL), D. Turpin (NAOC), X. Wang (THU),
and X. Zhang (THU)

report on behalf of the HETH group and GRANDMA collaboration.

We performed observations of LIGO/Virgo event S190426c (GCN #24237) with
the OAJ-T80 telescope operating in the visible located at Javalambre
astronomical observatory (Teruel, Spain).

The observation started on 04/26/19 21:40:23 UTC which corresponds
approximately to 6.3 hours after the GW trigger time.

We performed the following observations in r band:

+------------+------------+---------+---------+---------+
| Tstart     | Tend       | RA      | DEC     |   Proba |
| [UTC]      | [UTC]      | [deg]   | [deg]   |     [%] |
|------------+------------+---------+---------+---------|
| 2019-04-26 | 2019-04-26 | 0.000   | 84.000  |     1.0 |
| 21:40:23   | 21:43:24   |         |         |         |
| 2019-04-26 | 2019-04-26 | 340.000 | 84.000  |     0.7 |
| 21:43:52   | 21:46:52   |         |         |         |
| 2019-04-26 | 2019-04-26 | 330.000 | 86.000  |     0.9 |
| 21:50:01   | 21:53:01   |         |         |         |
| 2019-04-26 | 2019-04-26 | 0.000   | 82.000  |     0.4 |
| 21:53:32   | 21:56:32   |         |         |         |
| 2019-04-26 | 2019-04-26 | 0.000   | 86.000  |     0.8 |
| 21:56:59   | 22:00:00   |         |         |         |
| 2019-04-27 | 2019-04-27 | 309.600 | 56.000  |     0.5 |
| 01:20:38   | 01:23:38   |         |         |         |
| 2019-04-27 | 2019-04-27 | 305.280 | 46.000  |     0.5 |
| 01:28:57   | 01:31:58   |         |         |         |
| 2019-04-27 | 2019-04-27 | 301.935 | 30.000  |     0.4 |
| 01:34:18   | 01:37:19   |         |         |         |
| 2019-04-27 | 2019-04-27 | 300.760 | 28.000  |     0.4 |
| 01:37:46   | 01:40:46   |         |         |         |
| 2019-04-27 | 2019-04-27 | 306.000 | 48.000  |     0.4 |
| 01:41:17   | 01:44:18   |         |         |         |
| 2019-04-27 | 2019-04-27 | 313.846 | 64.000  |     0.5 |
| 01:47:29   | 01:50:29   |         |         |         |
| 2019-04-27 | 2019-04-27 | 309.231 | 64.000  |     0.4 |
| 01:50:56   | 01:53:57   |         |         |         |
| 2019-04-27 | 2019-04-27 | 299.627 | 26.000  |     0.4 |
| 01:54:34   | 01:57:35   |         |         |         |
| 2019-04-27 | 2019-04-27 | 300.789 | 32.000  |     0.4 |
| 01:58:03   | 02:01:04   |         |         |         |
| 2019-04-27 | 2019-04-27 | 304.186 | 44.000  |     0.4 |
| 02:01:33   | 02:04:33   |         |         |         |
| 2019-04-27 | 2019-04-27 | 302.013 | 34.000  |     0.4 |
| 02:07:46   | 02:10:47   |         |         |         |
| 2019-04-27 | 2019-04-27 | 306.783 | 50.000  |     0.4 |
| 02:11:16   | 02:14:16   |         |         |         |
| 2019-04-27 | 2019-04-27 | 310.737 | 58.000  |     0.4 |
| 02:14:48   | 02:17:48   |         |         |         |
| 2019-04-27 | 2019-04-27 | 302.897 | 36.000  |     0.4 |
| 02:18:22   | 02:21:22   |         |         |         |
| 2019-04-27 | 2019-04-27 | 303.830 | 38.000  |     0.4 |
| 02:25:13   | 02:28:14   |         |         |         |
| 2019-04-27 | 2019-04-27 | 298.537 | 24.000  |     0.4 |
| 02:28:43   | 02:31:43   |         |         |         |
| 2019-04-27 | 2019-04-27 | 308.571 | 54.000  |     0.4 |
| 02:32:20   | 02:35:20   |         |         |         |
+------------+------------+---------+---------+---------+

The probability refers to the 2D spatial probability of the GW (initial)
skymap enclosed in a given tile. Each tile is 1.4x1.4 degrees. These
observations cover about 11% of the cumulative probability of the skymap.
The typical limiting magnitude is 19.6 for a 180 s exposure.

The coverage map is available at:
https://grandma-owncloud.lal.in2p3.fr/index.php/s/jWlewyAy823F2sZ

No transients related to the GW event have been found when comparing sky
regions around GLADE galaxies with PS1 template observations.

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/).

HETH (High Energy Transients and Their Hosts) is funded by Spanish
National Research Grant of Excellence, Ramon y Cajal fellowships and
research funding, Juan de la Cierva Incorporation fellowships and
research funding (http://heth.iaa.es/).

Details on the OAJ-T80 telescope are available at http://oajweb.cefca.es

This circular is citable.