GRB 191019A: Zadko Telescope optical observations

We observed GRB 191019A (Simpson et al., GCN 26031) with the Zadko Telescope (Coward et al. 2017), starting at 2019 October the 19th at 15:20:23 UT (7 minutes 50 seconds after the trigger) under fair conditions. The object reported by Reva et al. (GCN 26036) is clearly visible in our images. However, we measure an R magnitude of 18.92 at the time reported by the GCN. Observations stopped one hour twenty three minutes after the burst, and during that time we do not see any variation on the light curve, similar to other teams (Perley et al., GCN 26039; Fynbo et al., GCN 26041; and Zhu et al., GCN 26059). At that position, the USNO catalog reports a source of magnitude R = 19.0, consistent with our findings. We conclude that this object is not the afterglow of GRB 191019A, but the host galaxy, as reported by Perley et al. (GCN 26062). The Zadko Telescope has been under refurbishment during the last year, and is still in recommissioning mode. This message can be cited. -- L'absence de virus dans ce courrier électronique a été vérifiée par le logiciel antivirus Avast. https://www.avast.com/antivirus