TITLE: GCN CIRCULAR NUMBER: 21501 SUBJECT: LIGO/Virgo G296853 TZAC TAROT observations DATE: 17/08/17 08:38:15 GMT FROM: Michel Boer at CESR-CNRS A. Klotz (IRAP/CNRS/UPS), R. Laugier (ARTEMIS/CNRS/UCA/OCA), K. Noysena (ARTEMIS/IRAP), M. Boer (ARTEMIS/CNRS/UCA/OCA) report on behalf of the TZAC collaboration: The field of the LVC candidate event G296853 was observed with TCH (TAROT-Chile field 1.9 x 1.9 deg2), TCA (TAROT Calern, field 1.9 x 1.9deg2) and TRE (TAROT La Réunion field 4.0 x 4.0 deg2) from Aug. 9, 2017 at 10h10m11s UT to Aug. 11, 2017, at 1h52m39s under good to variable conditions. 122 images lasting 120s each where generated. Fields observed at least twice have been checked for new sources with an upper limit of R > 17.5. For the other fields the analysis is still in progress. List of fields that were observed, centered on (RA, DEC) : TCH: 19.242 -20.171, 18.001 -22.035, 20.079 -22.035 from 2017-08-09T10:10:11 to 2017-08-09T10:36:30 TCA: 19.514 -20.193, 20.369 -22.057, 18.368 -22.060 from 2017-08-10T00:39:49 to 2017-08-10T02:40:38 TCH: 18.061 -22.126, 20.074 -22.119, 19.227 -20.264 from 2017-08-10T02:40:38 to 2017-08-10T04:17:29 TRE: 18.996 -30.232, 20.632 -26.034, 19.565 -30.232, 20.966 -26.033, 18.161 -34.430, from 2017-08-10T21:58:50 to 2017-08-11T01:50:39