TITLE: GCN GRB OBSERVATION REPORT NUMBER: 3546 SUBJECT: XRF 050509c: Optical monitoring DATE: 05/06/14 09:43:49 GMT FROM: Javier Gorosabel at IAA-CSIC J. Gorosabel (IAA-CSIC), J. Hjorth, B. L. Jensen, U. G. Jørgensen (NBI), J.-P. Beaulieu, A. Cassan (IAP), M. I. Andersen (AIP), J. Donatowicz (Tech. Uni. of Vienna), D. Watson, J. P. U. Fynbo, P. Jakobsson, J. M. Castro Cerón, H. Pedersen (NBI), report: "We have performed almost daily R-band monitoring of the XRF 050509c field (GCN Circ. 3402, HETE-2 trigger #3751) from May 15 to June 8. No significant rebrightening brighter than R ~ 22.5 has been detected at the afterglow position (GCN Circ. 3425) during the mentioned period. If XRF 050509c was related to a supernova similar to SN 1998bw, our observations would impose a lower redshift limit of z > 0.4. A combination of all late images (www.astro.ku.dk/~brian_j/grb/grb050509.95/) reveals a faint (R ~ 24) object coincident with the afterglow position, which we tentatively identify as the host galaxy of XRF 050509c."