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 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.