TITLE: GCN CIRCULAR NUMBER: 21558 SUBJECT: LIGO/Virgo G298048: TZAC TAROT Reunion (TRE) observations DATE: 17/08/18 13:04:25 GMT FROM: Michel Boer at CESR-CNRS A. Klotz (IRAP CNRS/UPS), R. Laugier, M. Boer, K. Noysena (ARTEMIS CNRS/UCA/OCA) report on behalf of the TZAC collaboration We have observed the initial error box with the TRE (TAROT-Reunion) Telescope located at Les Makes Observatory, La RĂ©union Island, France. Each image (no filter) lasts for 120s and covers a field of 4.2 x 4.2 deg2, with a magnitude limit of 17.0. Unfortunately the position of the candidate afterglow reported by Coulter et al. (LVC GCN 21529) was not in the position observable at that time given the automated generation of the fields, the mixed weather conditions, and the position of the GW candidate transient in the sky. We list below the log of the observations. Images are under analysis. Date RA DEC 2017-08-17T17:48:54 220.121 -43.833 2017-08-17T17:51:01 220.119 -43.832 2017-08-17T18:20:39 228.450 -48.036 2017-08-17T18:22:46 228.448 -48.035 2017-08-17T18:25:02 219.216 -52.230 2017-08-17T18:27:09 219.213 -52.228 2017-08-17T18:29:16 219.212 -52.226 2017-08-17T22:06:59 32.142 +40.179 2017-08-17T22:09:06 31.598 +40.180 2017-08-17T22:11:14 31.087 +40.183 2017-08-17T22:36:21 34.642 +42.385 2017-08-17T22:38:28 36.473 +40.141 2017-08-18T00:29:44 41.936 +40.144 2017-08-18T00:31:50 41.938 +40.143 2017-08-18T01:18:34 41.901 +40.145 2017-08-18T01:20:41 41.903 +40.145 2017-08-18T00:33:59 30.905 +40.147 2017-08-18T00:36:06 30.907 +40.147 2017-08-18T00:38:14 30.909 +40.147 2017-08-18T01:22:57 30.870 +40.151 2017-08-18T01:25:04 30.872 +40.151 2017-08-18T01:27:11 30.874 +40.151 2017-08-18T01:05:32 36.396 +40.145 2017-08-18T01:07:39 36.398 +40.145 2017-08-18T01:52:20 36.369 +40.149 2017-08-18T01:54:27 36.371 +40.150 2017-08-18T01:56:34 36.373 +40.151